I might get one of these.

Sold with ~2 Keys in Sweets for a Disco Beat Down Larrikin Robin(21 Keys)(19 Keys total)

http://backpack.tf/profiles/76561198039381855/#!/compare/1455696000/1455782400

Sold for a Terror-Watt Firewall Helmet(21.5 Keys)

http://backpack.tf/profiles/76561198101610113/#!/compare/1456819200/1456905600

Sold for a Kill-a-Watt Respectless Rubber Glove(22 Keys) and 3 Keys(25 Keys total)(B/O was 23)

http://backpack.tf/profiles/76561198071380407/#!/compare/1456819200/1456905600

http://backpack.tf/profiles/76561198071380407/#!/compare/1456819200/1456905600

http://www.tf2outpost.com/trade/27914768

Sales seem to fit, 19-23 Keys should be fine.

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