All these sales.

Sold for a Dead Presidents Pirate Bandana(14.5 Keys, rounding to 15)

http://backpack.tf/profiles/76561198177146885/#!/compare/1454227200/1455264000

Sold for a Steaming Medic's Mountain Cap(14 Keys)

http://backpack.tf/profiles/76561198267466993/#!/compare/1457938800/1458025200

Added 3 Keys for a Miami Nights Voodoo Juju(Slight Return)(18 Keys)(15 Keys total)

http://backpack.tf/profiles/76561198240424588/#!/compare/1456300800/1456387200

Sold for 14 Keys

http://backpack.tf/profiles/76561198125791160/#!/compare/1456041600/1456128000

Sold for a Strange Kritzkrieg(14 Keys at the time) and ~1 Key in Sweets(15 Keys total)

http://backpack.tf/profiles/76561198192602363/#!/compare/1454313600/1454400000

Sold for an Australium Pro KS Frontier Justice(~13.5 Keys, rounding to 14)

http://backpack.tf/profiles/76561198171495646/#!/compare/1459555200/1459728000

Sales seem to fit, 14-15 Keys should be fine.

Additional Proof/Counter-Proof/Constructive Criticism/Feedback is always appreciated.