Now this is more like it.

Sold with a Strange Festive Grenade Launcher(~3 Keys) for an Australium Grenade Launcher(21 Keys at the time)(18 Keys total)

http://backpack.tf/profiles/76561198267412440#!/compare/1458864000/1458950400

http://backpack.tf/profiles/76561198111608504#!/compare/1458864000/1458950400

Sold for a Terror-Watt Janissary Ketche(17.5 Keys) and ~0.5 Keys in Sweets(18 Keys total)

http://backpack.tf/profiles/76561198239513168#!/compare/1458630000/1459036800

Sold for 15 Keys(1 Key was in metal)

http://backpack.tf/profiles/76561198100918876#!/compare/1463443200/1463529600

Sold for a Steaming Professor's Peculiarity(17 Keys) and ~1 Key in Sweets(18 Keys total)

http://backpack.tf/profiles/76561198143584321#!/compare/1463788800/1463875200

Sales seem to fit, 15-18 Keys should be fine.

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