Item 1

https://backpack.tf/item/6824258632

I'll cover mp.tf sales at the end

Sale 1

https://backpack.tf/profiles/76561198173565391#!/compare/1690761600/1695859200

https://backpack.tf/profiles/76561198135388328#!/compare/1695859200/1695945600

Can only match a bit of ref

Sale 2

https://backpack.tf/profiles/76561198135388328#!/compare/1695772800/1695859200

https://backpack.tf/profiles/76561199012876815#!/compare/1695772800/1695859200

Looks like ~10 keys (Ref on buyer side)

Item 2

https://backpack.tf/item/5041240972

Sale 3

https://backpack.tf/profiles/76561199111470451#!/compare/1694822400/1694995200

https://backpack.tf/profiles/76561198858286641#!/compare/1694822400/1694908800

Can't match keys

Item 3

https://backpack.tf/item/4983019093

Sale 4

https://backpack.tf/profiles/76561198205194977#!/compare/1689897600/1690156800

https://backpack.tf/profiles/76561198850178158#!/compare/1690070400/1690156800

No clue

Ignoring all the bot trades... there's nothing of interest there

Sale 5

https://gladiator.tf/time-machine?item=Spooky%20Night%20Taunt:%20The%20Carlton&at=2023-09-06T12:10:30.000Z

https://backpack.tf/profiles/76561198850178158#!/compare/1693872000/1693958400

https://backpack.tf/profiles/76561198315119312#!/compare/1682467200/1694044800

~12 keys

Sale 6

https://backpack.tf/profiles/76561198315119312#!/compare/1696032000/1696118400

https://backpack.tf/profiles/76561198382267048#!/compare/1696032000/1696118400

Dumped for 6 keys

Mp.tf

https://marketplace.tf/items/tf2/1168;5;u3021

https://backpack.tf/item/7273206840

$23.99 / $2.01 = ~12 keys (Aug 8)

$23.99 / $2.03 = ~12 keys (Sep 30)

Total Sales

6, 10, 12, 12, 12

https://imgur.com/a/MWHkJ26

One of the 12 sales was dumped for 6, we can exclude those two

The Aug 8 sale was dumped to scrap.tf

That leaves us with a range of 10 - 12 keys c: