Now with the right math.

I wanted to show the sales in a simple way, but apparently that's impossible.

Also, first suggestion for something I never owned :D

Sale 1:

http://www.tf2outpost.com/trade/26076365 Sold with 4 keys for C9 Slope Scopers

Proof Panama was offered on Scopers: http://www.tf2outpost.com/trade/26018467

Seller's bp after: http://backpack.tf/profiles/76561198067163843?time=1434351600

History of Scopers: http://backpack.tf/item/2685324030

History of Panama: http://backpack.tf/item/551252194

Histories of keys: http://backpack.tf/item/3685397270

http://backpack.tf/item/3603888720

http://backpack.tf/item/2932007056

http://backpack.tf/item/2950719509

26-4=22 keys.

Sale 2:

http://www.tf2outpost.com/trade/25890824 Sold for Max's Head

History of Panama: http://backpack.tf/item/558085090

History of Max: http://backpack.tf/item/77610359

Taken as 24 keys.

Any support-counter proof/critiscism is always welcome.