Suggestion: Scorching Flames Pyromancer's Mask at 335–360 keys

https://backpack.tf/profiles/76561198097499917#!/compare/1594166400/1594252800 - Sold for a Circling TF Logo Noh Mercy (326) + a Purple Energy Handyman's Handle (~17) + a Duped Cloudy Moon Your Worst Nightmare (Buyer at 58) - Caps at Buyout

Buyout was 380 keys - https://bot.tf/stats/listings/MQ01J2EQ

Sale 4)

https://backpack.tf/profiles/76561198058857125#!/compare/1589760000/1593993600

https://backpack.tf/profiles/76561198063640894#!/compare/1593907200/1593993600 - Backpack purchase

Sale 5)

https://backpack.tf/item/339274874 https://marketplace.tf/items/tf2/316;5;u14

$777 / $1.99 = 390 keys, can't trace a buyout

Sale 6)

https://backpack.tf/item/280928399 https://marketplace.tf/items/tf2/316;5;u14

$500, below current buyers

Sale 7)

https://backpack.tf/profiles/76561198009208968#!/compare/1596585600/1596672000

https://backpack.tf/profiles/76561198232041512#!/compare/1596585600/1596672000 - Sold for 146 keys + a Tesla Coil Tipped Lid (>51) + a Tesla Coil Cranial Carcharodon (17) + Spelled Skull

https://csgo.backpack.tf/profiles/76561198009208968#!/compare/1480032000/1596672000

https://csgo.backpack.tf/profiles/76561198232041512#!/compare/1596412800/1596672000 - Plus Butterfly Knife | Night (Field-Tested) (~142) - Very likely to cap at buyout

Buyout was 360 https://bot.tf/stats/listings/MVQDL5RV

Mini for Knife:

https://steamcommunity.com/market/listings/730/%E2%98%85%20Butterfly%20Knife%20%7C%20Night%20%28Field-Tested%29

Lowest sale is £215.46 = ~121 keys

Highest sale £285.90 = ~162 keys

Mid-point is ~142 keys

Sale 8)

https://backpack.tf/profiles/76561197969363424#!/compare/1597536000/1597795200

https://backpack.tf/profiles/76561197970896022#!/compare/1597449600/1597881600

https://marketplace.tf/items/tf2/316;5;u14

$599.99 / $1.79 = 335 keys, no buyout traced

Sale 9)

https://backpack.tf/profiles/76561197993708178#!/compare/1597449600/1597536000

https://backpack.tf/profiles/76561197969363424#!/compare/1597276800/1597536000 - Bulk

Sale 10)

https://backpack.tf/profiles/76561198021736647#!/compare/1599955200/1600128000 - Using there

Sale 11)

https://backpack.tf/profiles/76561198129205357#!/compare/1599264000/1599350400

https://backpack.tf/profiles/76561198021736647#!/compare/1599350400/1599523200 - Sold for 221 keys + a Scorching Flames Modest Pile of Hat (would be around current at 125, should fit range anyways)

Buyout was 370 keys https://bot.tf/stats/listings/4ZP6NJ11

Sale 12)

https://backpack.tf/profiles/76561198059836930#!/compare/1596844800/1596931200

https://backpack.tf/profiles/76561198129205357#!/compare/1596844800/1596931200 - Sold for 325 keys, seller had paid 355 so excluding

Sale 13)

https://backpack.tf/profiles/76561198030343929#!/compare/1596240000/1596326400

https://backpack.tf/profiles/76561198030343929#!/compare/1596240000/1596326400 - Sold for 355, resold for 325 keys so excluding

Sale 14)

https://backpack.tf/profiles/76561198232041512#!/compare/1594252800/1594339200

https://backpack.tf/profiles/76561198210619136#!/compare/1594080000/1594339200

https://marketplace.tf/items/tf2/316;5;u14 https://gyazo.com/8a289a1a91f6a3fd16e18825eee5fed5

$700 / $2.00 = 350 keys - buyout was 350 keys https://bot.tf/stats/listings/MLV0X7VO

Sale 15) Duped Sale

https://backpack.tf/profiles/76561198197215790#!/compare/1596758400/1596844800 - Untrace

Sales 16 - 18)

https://marketplace.tf/items/tf2/316;5;u14

$534.98 / $2.01 = 266 keys

$639 / $1.81 = 353 keys

Sales:

~~266,~~ 335, 350, 353, 360, ~~380~~ and ~~390~~

Calling 266 low due to buyers

Calling 390 high due to unsolds, it was likely buyout capped but no buyout could be traced

380 looks to have been massive overpay, there was also a 350 seller at the same time. (Credits to Xergoyf) so to make the range more balanced I'm excluding it

Thanks =)