Using last month.

Sales 1 & 2:

Sold for $7 and $20 on marketplace.tf

https://marketplace.tf/items/30922;5;u3010

$7 is gonna be low, excluding.

20/1.95 = ~10.3

X = 10

Sale 3:

Sold for 9 keys (Buyer’s compare link)

Seller: https://backpack.tf/profiles/76561198048851745#!/compare/1532131200/1532217600

Buyer: https://backpack.tf/profiles/76561198220284497#!/compare/1532131200/1532390400

X = 9

Sale 4:

Sold to a quickbuyer for 7 keys + 15 ref

Seller: https://backpack.tf/profiles/76561198220284497#!/compare/1532390400/1532476800

Buyer: https://backpack.tf/profiles/76561198097271466#!/compare/1532390400/1532476800

X = 7.5

Sale 5:

Sold to a bot for 7 keys + 22 ref?

Seller: https://backpack.tf/profiles/76561198256956241#!/compare/1531526400/1531612800

Buyer: https://backpack.tf/profiles/76561198312583107#!/compare/1531526400/1531612800

Untraceable. Bot.tf confirms, but it is unreliable.

X = 7.5?

Sellers:

9 keys:

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

https://backpack.tf/item/6945023793

~9.55 keys:

https://i.imgur.com/dO9JEIL.png

https://backpack.tf/item/6626243618

~10.05 keys:

https://i.imgur.com/4SpqBBj.png

https://backpack.tf/item/6645356412

Sales at:

7.5

9

10

And an untraceable sale at 7.5.

7.5 is not a common trading point, excluding 7.5.

Excluding 10, due to the 2 sellers for cheaper, and due to it being a marketplace.tf sale. If it were a full pure sale, I would include it otherwise.

Going with 9 flat.