Sale 1 :

Before : http://backpack.tf/profiles/76561198100615262?time=1432969200

After : http://backpack.tf/profiles/76561198100615262?time=1433055600

Sold for a pro ks strange original ( sales average at 12 keys on classifieds ) + strange gibus ( 9 ) + 7 keys in items : 28 * 0.9 = 25 keys

Sale 2 : http://www.tf2outpost.com/trade/26418110

Before : http://backpack.tf/profiles/76561197995263987?time=1439622000

After : http://backpack.tf/profiles/76561197995263987?time=1439708400

Sold for 28 keys

Sale 3 :

Before : http://backpack.tf/profiles/76561198095894723?time=1436338800

After : http://backpack.tf/profiles/76561198095894723?time=1436425200

Sold for a Vivid Plasma Stainless Pot : 29 keys

Mini on the pot :

Before : http://backpack.tf/profiles/76561198119825885?time=1438066800

After : http://backpack.tf/profiles/76561198119825885?time=1438153200

Sold for a Circling Peace Sign Industrial Festivizer : 32 * 0.9 = 29 keys

Taking the range of 25 to 29 keys.

Supportive criticism welcome