Sale 1:

Sold for $39.99 on Marketplace.tf

https://marketplace.tf/items/30919;5;u3008

Can't find item's history

39.99/1.97 = ~20.3

X = 20

Sale 2:

Sold with Strange Spec. KS Night Owl Sniper Rifle (~1) for Strange Pro. KS Sniper Rifle (9) + ~1 key in items

Seller: https://backpack.tf/profiles/76561198276673530#!/compare/1521072000/1521158400

Buyer: https://backpack.tf/profiles/76561198190361110#!/compare/1520380800/1521158400

X = 9

Sale 3:

Sold to a quickbuyer for some amount of keys

Seller: https://backpack.tf/profiles/76561198143949670#!/compare/1523059200/1523318400

Buyer: https://backpack.tf/profiles/76561198091502579#!/compare/1523232000/1523318400

Sellers:

10 keys:

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

https://backpack.tf/item/6616223199

None on the SCM currently.

Sales at:

9

20

20 is gonna be an outlier given the seller at 10. Excluding 20.

Going with 9 flat.