I suppose.

Sold for a Steaming Cotton Head(30 Keys) and ~10 Keys in Sweets(40 Keys total)

http://backpack.tf/profiles/76561198071371521#!/compare/1469923200/1470009600

Added 3 Keys for an Australium Pro KS Eyelander(~32 Keys) and an Australium Spec KS Wrench(~22 Keys)(51 Keys total)

http://backpack.tf/profiles/76561198095902384#!/compare/1469664000/1469750400

Sold for 38 Keys(1 Key was in metal)

http://backpack.tf/profiles/76561198045354273#!/compare/1470960000/1471132800

Sold for a Circling Heart Stainless Pot(48 Keys)

http://backpack.tf/profiles/76561198105572423#!/compare/1465603200/1465776000

Sales seem to fit, 38-51 Keys should be fine.

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