Item 1

https://backpack.tf/item/15827065701

Sale 1

https://backpack.tf/profiles/76561198054976646#!/compare/1750118400/1750809600

https://backpack.tf/profiles/76561198349848918#!/compare/1750204800/1750291200

Dumped for an unknown amount

Item 2

https://backpack.tf/item/15746217695

Sale 2

https://backpack.tf/profiles/76561199476524319#!/compare/1749600000/1750809600

Probably SCM or a bulk buy?

Item 3

https://backpack.tf/item/15639930882

Sale 3

https://backpack.tf/profiles/76561199697283106#!/compare/1744675200/1745971200

https://backpack.tf/profiles/76561198139627699#!/compare/1744588800/1744675200

No clue

Sale 4

https://backpack.tf/profiles/76561198139627699#!/compare/1744848000/1744934400

https://backpack.tf/profiles/76561198307230510#!/compare/1744675200/1744934400

No clue

Sale 5

https://backpack.tf/profiles/76561198307230510#!/compare/1746144000/1746230400

https://backpack.tf/profiles/76561198191410787#!/compare/1745884800/1746144000

Probably 20 keys

Sale 6

https://backpack.tf/profiles/76561198191410787#!/compare/1746403200/1746489600

https://backpack.tf/profiles/76561199059632349#!/compare/1746403200/1746489600

Re-dumped for an unknown amount

Skipping past bot transfers...

Sale 7

https://backpack.tf/profiles/76561199059632349#!/compare/1747872000/1747958400

https://backpack.tf/profiles/76561198067903831#!/compare/1747267200/1748044800

Bought alongside some other stuff, can't tell for sure without a b/o...

Item 4

https://backpack.tf/item/15590476554

Sale 8

https://backpack.tf/profiles/76561198120420656#!/compare/1746403200/1749168000

https://backpack.tf/profiles/76561199110809353#!/compare/1746835200/1746921600

No clue

Sale 9

https://backpack.tf/profiles/76561199110809353#!/compare/1747440000/1747526400

https://backpack.tf/profiles/76561198311498888#!/compare/1747872000/1747958400

No clue

Then just bot stuff I can't trace...

Item 5

https://backpack.tf/item/15570977002

Skipping past bot transfers / tradeback...?

Sale 10

https://backpack.tf/profiles/76561199100485843#!/compare/1745366400/1746403200

https://backpack.tf/profiles/76561198376986207#!/compare/1720396800/1750636800

No clue

Item 6

https://backpack.tf/item/15544882516

Mannco.store stuff

Item 7

https://backpack.tf/item/15544067248

Sale 11

https://backpack.tf/profiles/76561198047141747#!/compare/1744156800/1744243200

https://backpack.tf/profiles/76561198317074062#!/compare/1744156800/1744243200

No clue

Item 8

https://backpack.tf/item/15504301470

Mannco.store

Item 9

https://backpack.tf/item/15495668107

Sale 12

https://backpack.tf/profiles/76561198025018960#!/compare/1748131200/1748217600

https://backpack.tf/profiles/76561198859721638#!/compare/1748044800/1748131200

Bulk for a Non-Craftable Strange Spine-Chilling Skull 2011

Sale 13

https://backpack.tf/profiles/76561198859721638#!/compare/1748563200/1748649600

https://backpack.tf/profiles/76561198124602785#!/compare/1748304000/1748822400

12 keys + Brother Mann + Cranial Cowl + Alcoholic Automaton

=====================================================================================

Brother Mann => ~2 keys

https://gladiator.tf/sales?item=Brother%20Mann&at=2025-05-31T10:00:22.081Z

=====================================================================================

Cranial Cowl => ~1.5 keys

https://gladiator.tf/sales?item=Cranial%20Cowl&at=2025-05-31T10:00:22.081Z

=====================================================================================

Alcoholic Automaton => ~1.5 keys

https://gladiator.tf/sales?item=Alcoholic%20Automaton&at=2025-05-31T10:00:22.081Z

=====================================================================================

12 + 2 + 1.5 + 1.5 = ~17 keys

Item 10

https://backpack.tf/item/15492031622

Sale 14

https://backpack.tf/profiles/76561198054159742#!/compare/1745193600/1745280000

https://backpack.tf/profiles/76561198060189392#!/compare/1745107200/1745193600

Just an inv transfer

Item 11

https://backpack.tf/item/15401699412

Sale 15

https://backpack.tf/profiles/76561198349848918#!/compare/1745971200/1746057600

https://backpack.tf/profiles/76561198061069783#!/compare/1747440000/1747785600

No clue

Item 12

https://backpack.tf/item/15296946867

Sale 16

https://backpack.tf/profiles/76561198395841016#!/compare/1743811200/1743897600

https://backpack.tf/profiles/76561199101376092#!/compare/1746403200/1746576000

No clue

Item 13

https://backpack.tf/item/15292321786

Sale 17

https://backpack.tf/profiles/76561199203680409#!/compare/1749081600/1749168000

https://backpack.tf/profiles/76561199069442401#!/compare/1748822400/1749168000

16 keys match

Item 14

https://backpack.tf/item/15587351955

Sale 18

https://backpack.tf/profiles/76561199795001865#!/compare/1743724800/1743897600

https://backpack.tf/profiles/76561198988028405#!/compare/1743724800/1743811200

No clue

Sale 19

https://backpack.tf/profiles/76561198988028405#!/compare/1743811200/1743897600

https://backpack.tf/profiles/76561198009914215#!/compare/1743638400/1744156800

No clue

Skipping past repeat instances...

Sale 20

https://backpack.tf/profiles/76561198009914215#!/compare/1748390400/1748736000

https://backpack.tf/profiles/76561198972511784#!/compare/1748649600/1748736000

No clue

Sale 21

https://backpack.tf/profiles/76561198972511784#!/compare/1748649600/1748736000

https://backpack.tf/profiles/76561199017959799#!/compare/1748736000/1748995200

No clue

Sale 22

https://backpack.tf/profiles/76561199017959799#!/compare/1749081600/1749168000

https://backpack.tf/profiles/76561199243508401#!/compare/1748908800/1749168000

No clue

Sale 23

https://backpack.tf/profiles/76561199243508401#!/compare/1748908800/1749168000

https://backpack.tf/profiles/76561199380923769#!/compare/1749427200/1749513600

No clue

Sale 24

https://backpack.tf/profiles/76561199380923769#!/compare/1749513600/1749600000

https://backpack.tf/profiles/76561198977721610#!/compare/1749513600/1749600000

No clue

Sale 25

https://backpack.tf/profiles/76561198977721610#!/compare/1749859200/1749945600

https://backpack.tf/profiles/76561198091502579#!/compare/1749600000/1749945600

Bulk buy

Mp.tf

https://marketplace.tf/items/tf2/31497;5;u370

https://backpack.tf/item/15288291924

https://backpack.tf/item/15669839638

https://backpack.tf/item/15590631353

$39.99 / $1.89 = ~21 keys (Apr 2)

$33.99 / $1.91 = ~18 keys (Apr 12)

$34.99 / $1.92 = ~18 keys (Apr 30)

$39.99 / $1.92 = ~21 keys (May 2)

$44.99 / $1.93 = ~23 keys (May 3)

$44.99 / $1.93 = ~23 keys (May 11)

$44.99 / $1.94 = ~23 keys (May 28)

$44.99 / $1.95 = ~23 keys (Jun 5)

$44.99 / $1.99 = ~23 keys (Jun 22)

Total Sales

16, 17, 18, 18, 20, 21, 21, 23, 23, 23, 23, 23

https://imgur.com/a/B4bZGMH

Honestly, I think a full range here with all the values if fine given the number of mp sales @ 23

Taking 16 - 23 keys c:

Unsolds:

https://backpack.tf/item/15827065701 - 18

https://backpack.tf/item/15242325827 - 18

https://backpack.tf/item/15292321786 - $44.44

https://backpack.tf/item/15504301470 - $44.44

https://backpack.tf/item/15587351955 - $44.44