Sale 1:

Sold for $40 on marketplace.tf

https://marketplace.tf/items/30658;5;u59

https://backpack.tf/item/6787764878 - Most likely this history, not sure though. Linked in “Other Sales”.

http://manic.tf/keyprice/?at=2018-06-04 - $40 / $1.95 = 20.51 keys

https://backpack.tf/item/6787764878

X = 21

Sale 2:

Sold to scrap for 20 keys + more than half a key in metal

https://backpack.tf/profiles/76561198080179568#!/compare/1530403200/1530489600

https://backpack.tf/profiles/76561198135388328#!/compare/1530403200/1530489600

https://backpack.tf/item/6945758977

X = 21

Sale 3:

Sold to scrap.tf for 21 keys + some metal

https://backpack.tf/profiles/76561198029074524#!/compare/1535068800/1535155200

https://backpack.tf/profiles/76561198135388328#!/compare/1535068800/1535155200

https://backpack.tf/item/7075547761

X = 21

Other Sales:

#1

Quickbought off the SCM

https://backpack.tf/profiles/76561198110827768#!/compare/1529798400/1529884800

https://backpack.tf/profiles/76561198080179568#!/compare/1529798400/1529884800

https://backpack.tf/item/6945758977

#2

Untraceable, bought off scrap and dumped on tf2mart

https://backpack.tf/profiles/76561198135388328#!/compare/1530835200/1530921600

https://backpack.tf/item/6937233378

#3

Untraceable. Most likely sold on mp.tf

https://backpack.tf/profiles/76561198224899376#!/compare/1527638400/1527724800

https://backpack.tf/profiles/76561198066330410#!/compare/1527984000/1528070400

https://backpack.tf/item/6787764878

#4

Untraceable, probably gambled

https://backpack.tf/profiles/76561198066330410#!/compare/1527984000/1528070400

https://backpack.tf/profiles/76561198030214998#!/compare/1527811200/1528070400

https://backpack.tf/item/6787764878

#5

Untraceable, probably gambled again.

https://backpack.tf/profiles/76561198030214998#!/compare/1528070400/1528243200

https://backpack.tf/profiles/76561198289262378#!/compare/1527984000/1528070400

https://backpack.tf/item/6787764878

#6

Untraceable, probably dumped on SCM

https://backpack.tf/profiles/76561197963394917#!/compare/1528070400/1528156800

https://backpack.tf/profiles/76561197984635963#!/compare/1522108800/1529798400

https://backpack.tf/item/6787764878

#7

Dumped on tf2mart

https://backpack.tf/item/6359793841

Sellers:

~22 keys: - Scrap.tf

https://i.imgur.com/85lKuaW.png

https://backpack.tf/item/7075547761 - Couple days

30 keys:

https://i.imgur.com/pwJhmso.png

https://backpack.tf/item/6744041397

Sales at:

21 (3x)

2 of the sales may have been scrap.tf sales, but there are no higher sales, and it appears to be a common trading point.

Going with 21 flat.