Credits to Auberon and Shuffle Spy for reviewing an inane amount of sales, and Jamal for minis as mentioned

https://mannco.store/item/5853

$700 / $1.67 = 419.16 keys

https://marketplace.tf/items/tf2/30658;5;u99

$599.99 / $1.81 = 331.49 keys

https://backpack.tf/profiles/76561198068640109#!/compare/1630972800/1631059200

https://backpack.tf/profiles/76561198164651434#!/compare/1630886400/1630972800

Beams HKC + Keys

https://backpack.tf/profiles/76561198164651434#!/compare/1631059200/1631145600

https://backpack.tf/profiles/76561198237456838#!/compare/1629504000/1631145600

268

https://backpack.tf/profiles/76561198237456838#!/compare/1632182400/1632268800

https://backpack.tf/profiles/76561198449473770#!/compare/1632182400/1632268800

360

https://backpack.tf/profiles/76561198449473770#!/compare/1632182400/1632268800

https://backpack.tf/profiles/76561199195627878#!/compare/1632182400/1632268800

Resold for 331

https://backpack.tf/profiles/76561198106372188#!/compare/1626998400/1627084800

https://backpack.tf/profiles/76561198862273718#!/compare/1626998400/1627084800

285

https://backpack.tf/profiles/76561198862273718#!/compare/1627084800/1627430400

https://backpack.tf/profiles/76561198129205357#!/compare/1627171200/1627430400

Unknown

https://backpack.tf/profiles/76561198129205357#!/compare/1631404800/1631491200

https://backpack.tf/profiles/76561198160856661#!/compare/1631404800/1631491200

GPan Bulk

https://backpack.tf/profiles/76561198114402400#!/compare/1634169600/1634256000

https://backpack.tf/profiles/76561198127924408#!/compare/1633996800/1634256000

1 for 1 with Arcana Mountain Cap

https://backpack.tf/profiles/76561198096762393#!/compare/1626566400/1630281600

https://backpack.tf/profiles/76561198273331466#!/compare/1630195200/1630281600

Unknown

https://backpack.tf/profiles/76561198273331466#!/compare/1630195200/1630281600

https://backpack.tf/profiles/76561198061402527#!/compare/1630195200/1630281600

150 pure + Starduster (5) + The Dark Doorway Defragmenting Hard Hat 17% (169) + Static Shock HiF Taunt +

Toxic Terrors Fubar + Reindoonicorn Rancher Jumping Jack + Arctic Aurora Skullcracker + Ascension Brewed Victory

Buyorders alone caps his b/o

https://i.imgur.com/0mVV59u.png

https://gladiator.tf/listings/612c7aa5f2ace1cbc89bd236

B/o of 359 at the time

https://backpack.tf/profiles/76561198956272094#!/compare/1629158400/1629244800

https://backpack.tf/profiles/76561198114402400#!/compare/1629158400/1629244800

Unknown

https://backpack.tf/profiles/76561198114402400#!/compare/1630108800/1630195200

https://backpack.tf/profiles/76561198045343680#!/compare/1630108800/1630195200

1 for 1 with Steaming ants (361)

https://backpack.tf/profiles/76561198045343680#!/compare/1631491200/1631577600

https://backpack.tf/profiles/76561198345273748#!/compare/1631404800/1631577600

Use toward HF Noble

https://backpack.tf/profiles/76561198345273748#!/compare/1631577600/1632182400

https://backpack.tf/profiles/76561199195627878#!/compare/1632182400/1633046400

Sold for 350 pure

https://backpack.tf/profiles/76561198153789411#!/compare/1630627200/1630713600

https://backpack.tf/profiles/76561198083134207#!/compare/1630627200/1630713600

Used toward Arc Bucc Bicorne

https://backpack.tf/profiles/76561198083134207#!/compare/1630713600/1630800000

https://backpack.tf/profiles/76561198114402400#!/compare/1630713600/1630800000

Unknown

https://backpack.tf/profiles/76561198114402400#!/compare/1632960000/1633046400

https://backpack.tf/profiles/76561198096704153#!/compare/1632960000/1633046400

Sold for pure, asking pyro for amount

https://backpack.tf/profiles/76561198002757046#!/compare/1629244800/1629331200

https://backpack.tf/profiles/76561198138753669#!/compare/1629244800/1629417600

340

https://backpack.tf/profiles/76561198064873161#!/compare/1628726400/1628812800

https://backpack.tf/profiles/76561198140316312#!/compare/1628726400/1628812800

Use toward SF Veil

https://backpack.tf/profiles/76561198140316312#!/compare/1630368000/1630454400

https://backpack.tf/profiles/76561198251805358#!/compare/1630368000/1630454400

370

https://backpack.tf/profiles/76561198153224095#!/compare/1627689600/1628467200

https://backpack.tf/profiles/76561198054966400#!/compare/1627257600/1628121600

224

https://backpack.tf/profiles/76561198054966400#!/compare/1632528000/1632873600

https://backpack.tf/profiles/76561198070839268#!/compare/1632873600/1632960000

Unknown

https://backpack.tf/profiles/76561198070839268#!/compare/1633305600/1633737600

https://backpack.tf/profiles/76561198345436872#!/compare/1633651200/1633824000

390

https://backpack.tf/profiles/76561198345436872#!/compare/1633910400/1634083200

https://backpack.tf/profiles/76561198104134966#!/compare/1633478400/1634083200

https://steamuserimages-a.akamaihd.net/ugc/1737819515054759944/15E22D6E42DC74B1408FB6510BACF145B58210B9/

https://i.imgur.com/3X8xKCr.png

450

https://backpack.tf/profiles/76561198275478002#!/compare/1632096000/1632182400

https://backpack.tf/profiles/76561199195627878#!/compare/1632182400/1633046400

355

https://backpack.tf/profiles/76561198166162405#!/compare/1628640000/1630022400

https://backpack.tf/profiles/76561198057696126#!/compare/1629849600/1630022400

345 pure

https://backpack.tf/profiles/76561198141382684#!/compare/1627084800/1627257600

https://backpack.tf/profiles/76561198141189020#!/compare/1627171200/1627257600

290

https://backpack.tf/profiles/76561198141189020#!/compare/1627257600/1627516800

https://backpack.tf/profiles/76561198057355049#!/compare/1627430400/1627516800

Hotrod would put this under buyers, excluding

https://backpack.tf/profiles/76561198057355049#!/compare/1627776000/1627948800

https://backpack.tf/profiles/76561198048724906#!/compare/1627862400/1627948800

Use toward DB Dirty Rag

Assuming it was dumped afterwards to Sunjar

https://backpack.tf/profiles/76561198139171368#!/compare/1628899200/1628985600

https://backpack.tf/profiles/76561198843408761#!/compare/1628899200/1628985600

Unknown

https://backpack.tf/profiles/76561198843408761#!/compare/1630368000/1630454400

https://backpack.tf/profiles/76561198367551064#!/compare/1630368000/1630454400

Basically traded for a black painted version = Excluding

https://backpack.tf/profiles/76561198367551064#!/compare/1630540800/1630627200

https://backpack.tf/profiles/76561198318099621#!/compare/1630454400/1630627200

364

https://backpack.tf/profiles/76561198418740133#!/compare/1628208000/1628553600

https://backpack.tf/profiles/76561198072465094#!/compare/1628467200/1628553600

293

https://backpack.tf/profiles/76561198072465094#!/compare/1632182400/1632355200

https://backpack.tf/profiles/76561198083134207#!/compare/1632268800/1632355200

Use toward BF Beak

https://backpack.tf/profiles/76561198083134207#!/compare/1632441600/1632528000

https://backpack.tf/profiles/76561198449473770#!/compare/1632355200/1632787200

347

https://backpack.tf/profiles/76561198449473770#!/compare/1632787200/1633564800

https://backpack.tf/profiles/76561199195627878#!/compare/1632528000/1633046400

Unknown

https://backpack.tf/profiles/76561198143091286#!/compare/1633996800/1634083200

https://backpack.tf/profiles/76561198062420532#!/compare/1633996800/1634083200

Use toward GE Beak

https://backpack.tf/profiles/76561198062420532#!/compare/1634169600/1634256000

https://backpack.tf/profiles/76561198442469360#!/compare/1634169600/1634256000

https://backpack.tf/suggestion/61733df7e5ac1239d72d15ab Handle

https://backpack.tf/suggestion/61734b31f1e65a4379061fc6 Peak

https://backpack.tf/suggestion/61734bcffe68e00fa548498a Slope

https://backpack.tf/suggestion/617354c63daa5017212f8ab8 Beenie

D@D Handle (60.5) + DBD Peak (155) + GE Slope (62.5) + Beams Coldsnap + Frozen Icefall Beenie (102.5) + GE Woodsman (75)

https://gladiator.tf/listings/6167b289bc6c1b24d0afb347 B/o of 469

Not even having to price the Coldsnap, he would cap his buyout @ 469

https://backpack.tf/profiles/76561198339835923#!/compare/1634169600/1634256000

https://backpack.tf/profiles/76561198850178158#!/compare/1634169600/1634256000

Unknown, I know that he dumped the aussies but no clue what that bot ended up getting for the translator

https://backpack.tf/profiles/76561198046588996#!/compare/1627084800/1627776000

https://backpack.tf/profiles/76561198148511293#!/compare/1627084800/1627171200

Unknown

https://backpack.tf/profiles/76561198114402400#!/compare/1632096000/1632182400

https://backpack.tf/profiles/76561199195627878#!/compare/1632182400/1633046400

Unknown

https://backpack.tf/profiles/76561198157928445#!/compare/1631318400/1631750400

https://backpack.tf/profiles/76561198085861958#!/compare/1631664000/1631750400

No clue

https://backpack.tf/profiles/76561198085861958#!/compare/1631664000/1631750400

https://backpack.tf/profiles/76561197994721444#!/compare/1631664000/1631750400

Looks like it sold for 342

https://backpack.tf/profiles/76561198046496465#!/compare/1630540800/1630972800

https://backpack.tf/profiles/76561197965479730#!/compare/1630713600/1630972800

Regardless if keys were added to this beanie, this would def put it under buyers

https://backpack.tf/profiles/76561198044254513#!/compare/1627171200/1627257600

https://backpack.tf/profiles/76561198139171368#!/compare/1627084800/1627171200

Bulk for DF Modest

https://backpack.tf/profiles/76561198139171368#!/compare/1629504000/1629676800

https://backpack.tf/profiles/76561198313950579#!/compare/1629590400/1629676800

Not a clue

https://backpack.tf/profiles/76561198313950579#!/compare/1631923200/1632009600

https://backpack.tf/profiles/76561198077555267#!/compare/1631836800/1631923200

No clue

https://backpack.tf/profiles/76561198077555267#!/compare/1632096000/1632182400

https://backpack.tf/profiles/76561199195627878#!/compare/1632182400/1633046400

350 pure

https://backpack.tf/profiles/76561198418740133#!/compare/1627948800/1628035200

https://backpack.tf/profiles/76561199113807382#!/compare/1627776000/1628035200

290

https://backpack.tf/profiles/76561198114402400#!/compare/1633046400/1633132800

https://backpack.tf/profiles/76561198816854661#!/compare/1633132800/1633219200

Sweets + Aussies + Nebula Hat Full of Hot Air (127.5) + Isotope Festivized Killstreak Seriously Snowed Shotgun (Well-Worn ) (Need mini) + Spellbound Aspect Burstchester

No mini on Shotty

127.5 + 18 + 23 in sweets + Aussie Flame (28) + Aussie Sniper (34) + Eyelander (85) + Scatter (42) + Knife (21) + Minigun (26) +

Grenade (21) + Amby (12)

This before shotty would make it 440

He had two possible buyouts of 450-470 and he owns/owned multiple ones at the time so very hard to determine.

Excluding due to it being high and no minis for shotty

https://backpack.tf/profiles/76561197966756586#!/compare/1632528000/1632700800

https://backpack.tf/profiles/76561198086071842#!/compare/1632528000/1632700800

359

https://backpack.tf/profiles/76561198372616713#!/compare/1627257600/1627430400

https://backpack.tf/profiles/76561199068665221#!/compare/1627257600/1627430400

295

https://backpack.tf/profiles/76561198838788284#!/compare/1627603200/1627689600

https://backpack.tf/profiles/76561199068665221#!/compare/1627603200/1627689600

Use toward KS Inspector

https://backpack.tf/profiles/76561198082401774#!/compare/1627430400/1627516800

https://backpack.tf/profiles/76561198146046621#!/compare/1627430400/1627516800

No clue

https://backpack.tf/profiles/76561198146046621#!/compare/1627603200/1627689600

https://backpack.tf/profiles/76561198069239963#!/compare/1628035200/1628208000

No clue

https://backpack.tf/profiles/76561198069239963#!/compare/1628553600/1628640000

https://backpack.tf/profiles/76561198074120641#!/compare/1628553600/1628640000

340 pure

https://backpack.tf/profiles/76561198074120641#!/compare/1628812800/1628899200

https://backpack.tf/profiles/76561198022330462#!/compare/1628812800/1628899200

348

Shuffle Spy:

https://backpack.tf/profiles/76561199133932832#!/compare/1635465600/1635552000 - ?

https://backpack.tf/profiles/76561198074718149#!/compare/1635552000/1635638400 - 470 Keys

https://backpack.tf/profiles/76561198114402400#!/compare/1637452800/1637712000 - Buncha stuff that's 460 Keys minimum, 500 Keys maximum

https://gladiator.tf/listings/6199e02a87ebf66260152763 - Buyout of 500 Keys on the 460 Key minimum sale

https://backpack.tf/profiles/76561198076509265#!/compare/1634428800/1635811200 - ?

https://backpack.tf/profiles/76561198061836787#!/compare/1635724800/1635811200 - ?

https://backpack.tf/profiles/76561198442469360#!/compare/1634947200/1635120000 - ?

https://backpack.tf/profiles/76561198267929615#!/compare/1637712000/1637971200 - ?

https://backpack.tf/profiles/76561198069183333#!/compare/1638057600/1638144000 - Backpack dump

https://backpack.tf/profiles/76561198396499936#!/compare/1636588800/1636675200 - Bulk sale

https://backpack.tf/profiles/76561197962471855#!/compare/1636848000/1636934400 - The Classy was traded back, so don't use this

https://backpack.tf/profiles/76561199210713871#!/compare/1636934400/1637020800 - ?

https://backpack.tf/profiles/76561198096404008#!/compare/1635984000/1636070400 - Death at Dusk Brotherhood of Arms

https://gladiator.tf/listings/6182f664d8dd5bade358c632 - Buyout of 465 Keys for the Brotherhood sale

https://backpack.tf/profiles/76561198157279796#!/compare/1636070400/1636156800 - ?

https://backpack.tf/profiles/76561198061489334#!/compare/1635638400/1635811200 - 223 Keys and 6 Unusuals worth at least 231 Keys

https://gladiator.tf/listings/6180a0c994aea1237f8142a2 - The 223 Keys + Unusuals trade is probably capped by the buyout of 470 Keys

https://backpack.tf/profiles/76561199113807382#!/compare/1634342400/1635033600 - ?

https://backpack.tf/profiles/76561198170312259#!/compare/1635033600/1635120000 - Bulk sale

https://backpack.tf/profiles/76561199139031975#!/compare/1635206400/1635292800 - Bulk sale

https://backpack.tf/profiles/76561198263190057#!/compare/1635033600/1635292800 - ?

https://backpack.tf/profiles/76561198142497459#!/compare/1636416000/1636502400 - 243 Keys + Duped Burning Samur-Eye + Daydream Beenie

https://gladiator.tf/listings/61879d1e549433f1460ff9a0 - Buyout of 469 Keys for the Samur-Eye sale

https://backpack.tf/item/10419313517 - Sold for $999.99 (535 Keys)

https://backpack.tf/profiles/76561198067624077#!/compare/1636848000/1636934400 - 398 Keys

https://backpack.tf/profiles/76561198067624077#!/compare/1637193600/1637280000 - 6 Unusuals + 11 Keys

https://gladiator.tf/listings/61979e9142396eb138a777db - Buyout of 500 on the Unusuals + 11 Keys sale

https://backpack.tf/profiles/76561199195627878#!/compare/1635638400/1633046400 - ?

https://backpack.tf/profiles/76561198449473770#!/compare/1635638400/1635984000 - ?

https://backpack.tf/profiles/76561198275478002#!/compare/1638403200/1638489600 - Frostbite Executioner + Planets Yellow Belt + 17 Keys

https://backpack.tf/suggestion/61a94aacb3310104e9414272 - The Planets Yellow Belt has a suggestion open at 100 Keys

https://gladiator.tf/listings/61a89f7738f6510d8d895429 - Buyout of 545 Keys for the Executioner and Belt sale

https://backpack.tf/profiles/76561198251805358#!/compare/1636329600/1636416000 - ?

https://backpack.tf/profiles/76561198067624077#!/compare/1636588800/1636675200 - 435 Keys

https://backpack.tf/profiles/76561198140316312#!/compare/1636848000/1636934400 - Better for the Whoopee

https://backpack.tf/profiles/76561198140316312#!/compare/1637625600/1637712000 - PE War Pig + 150 Keys + 11 Max's Heads

https://gladiator.tf/listings/619d6f6ca5cb9da429b9539e - The War Pig sale is capped by the buyout of 550 Keys

https://backpack.tf/profiles/76561198127924408#!/compare/1635206400/1635292800 - Better for the Halogen

https://backpack.tf/profiles/76561198069183333#!/compare/1637193600/1637280000 - ?

https://backpack.tf/item/4331198997 - Sold for $869.99 (465 Keys)

https://backpack.tf/profiles/76561198170440245#!/compare/1635811200/1635984000 - ?

https://backpack.tf/profiles/76561198043082159#!/compare/1636588800/1636675200 - 404 Keys + whatever this Pistol sold for

https://backpack.tf/profiles/76561197991111981#!/compare/1636588800/1636675200 - 26 Keys and the Pistol are from the Hazard trade

https://backpack.tf/profiles/76561198051680717#!/compare/1636416000/1636502400 - Bulk sale

https://backpack.tf/profiles/76561198146627532#!/compare/1638057600/1638144000 - Sulphurous Brainiac Hairpiece (351 Keys) + 120 Keys

https://backpack.tf/profiles/76561198057897812#!/compare/1638057600/1638144000 - The Brainiac sold for 351 Keys

https://backpack.tf/profiles/76561198161711912#!/compare/1638489600/1638576000 - ?

https://backpack.tf/profiles/76561198161711912#!/compare/1638662400/1638748800 - Buncha stuff that's 500 Keys minimum

https://gladiator.tf/listings/61ad41efa5553e2ff24e2db7 - Buyout of 534 Keys for the 500 Key minimum sale

https://marketplace.tf/items/tf2/30658;5;u99 - Second $869.99 (465 Keys) sale that I can't find the history for

All excluded sales below 385:

224 268 285 290 290 293 295 331 331 340 340 342 345 347 348 350 350 355 359 359 360 361 364 370

All sales above 385:

390, 398, 404 + Pistol, 435, 440, 450 x2, max 465, 465 x2, max 469, 470 x2, 471, 460 - 500, max 500, 500 - 534, 535, max 545, 550, 550

To not exclude every single low sale, a range of 390 to 550 would work to encompass everything.

New sales since Shuffle Spy's comment:

https://backpack.tf/profiles/76561198275478002#!/compare/1638748800/1638835200

https://backpack.tf/profiles/76561198114402400#!/compare/1638748800/1638835200

440 keys

https://backpack.tf/profiles/76561198140316312#!/compare/1638921600/1639008000

https://backpack.tf/profiles/76561198068925028#!/compare/1638921600/1639008000

Looks to be ~209 keys + Max Head (~27) + Frostbite Little Buddy (55 bo) + Vivid Plasma Bonk Boy (215 bo) + Terror-Watt Whirly Warrior (33 bo)

B/O at 550 keys: https://gladiator.tf/listings/61b130ebc8f0f2e60ee84650

Safe to say this would almost certainly cap at 550. This supports the suggested high end despite a seller at 500 and the lower 440 sale.

Taking 390-550 keys as per Shuffle Spy's comments.