Using last 30 days

Sale 1:

Sold for 11 keys

Seller: https://backpack.tf/profiles/76561198170109470#!/compare/1522022400/1522800000

Buyer: https://backpack.tf/profiles/76561198162712360#!/compare/1522627200/1522713600

X = 11

Sale 2:

Bot.tf sale at 8 keys

https://i.imgur.com/DKHkJ4F.png

Couldn't find item history

X = 8

Sale 3:

Sold for $14.1 on Marketplace.tf

https://marketplace.tf/items/1110;5;u3009

Can't find item's history

14.1/1.97 = ~7.16

X = 7

Sellers:

12 keys:

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

https://backpack.tf/item/6729526902

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

https://backpack.tf/item/5021758685

https://i.imgur.com/aVW81Fz.png

https://backpack.tf/item/3133397995

https://i.imgur.com/uP03B9Z.png

https://backpack.tf/item/2721991901

~13.9 keys:

https://i.imgur.com/EeFaiN2.png

https://backpack.tf/item/2690423447

18 keys:

http://www.tf2outpost.com/trade/29617650

20 keys:

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

https://backpack.tf/item/2882202544

49 keys:

https://i.imgur.com/mH5Bl1c.png

https://backpack.tf/item/4067347534

69 keys:

http://www.tf2outpost.com/trade/29579401

75 keys:

http://www.tf2outpost.com/trade/27764682

SCM:

https://i.imgur.com/k4oHVP1.png

$21.69 (~8.78 keys)

$21.91 (~8.87 keys)

$22.21 (~8.99 keys)

$23.76 (~9.62 keys)

$24.86 (~10.06 keys)

$25.41 (~10.29 keys)

(rest aren't important)

Sales at:

7

8

11

Quickbuyers at 7+ keys

https://i.imgur.com/IzywU9q.png

Excluding 7.

Going with 8-11.

Buyer has appeared at 8 keys:

https://i.imgur.com/efF8vAY.png

Gonna wait a bit and see if it remains