Sale 1:

Sold to a quickbuyer for 35 keys

Seller: https://backpack.tf/profiles/76561198073435210#!/compare/1555286400/1555372800

Buyer: https://backpack.tf/profiles/76561198119634686#!/compare/1555200000/1555286400

https://backpack.tf/item/7138464944

X = 35

Sale 2:

Sold to a quickbuyer for 35 keys

Seller: https://backpack.tf/profiles/76561198050849650#!/compare/1555286400/1555372800

Buyer: https://backpack.tf/profiles/76561198337734785#!/compare/1555200000/1555286400

https://backpack.tf/item/6873926028

X = 35

Other Sales:

https://backpack.tf/item/7373994393 (#1)

https://backpack.tf/item/6969236186 (#2, excluded gambling)

https://backpack.tf/item/6873926028 (#3)

#1

Untraceable

https://backpack.tf/profiles/76561198129860851#!/compare/1555459200/1555545600

https://backpack.tf/profiles/76561198312583107#!/compare/1555459200/1555545600

https://i.imgur.com/i9OOBbc.png - labelled as ~33 keys on bot.tf

#2

Untraceable

https://backpack.tf/profiles/76561198051798340#!/compare/1556841600/1556928000

https://backpack.tf/profiles/76561198342161127#!/compare/1556841600/1556928000

#3

Untraceable

https://backpack.tf/profiles/76561198337734785#!/compare/1555372800/1555459200

https://backpack.tf/profiles/76561198311498888#!/compare/1555372800/1555459200

Sellers:

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

https://backpack.tf/item/7373994393 - 35 keys

https://backpack.tf/item/7138464944 - 42 keys

Sales at:

35 (2x)

Both sales went to quickbuyers, but there are currently no buyers anywhere near that price, no sales for higher, and there’s a seller at 35 included above.

Going with 35 flat.