So I found this mobile game called neko atsume and the point is to put out toys for cats and they'll come in and play with the ones you give them and it's adorable and i love it

Sold for a Max's Severed Head(19 Keys) and ~6 Keys in Sweets(25 Keys total)

http://backpack.tf/profiles/76561198080179568#!/compare/1485043200/1485129600

Sold for an Australium Pro KS Sniper Rifle(~36 Keys)(B/O was 30)

http://backpack.tf/profiles/76561198099451468#!/compare/1484265600/1484438400

http://www.tf2outpost.com/trade/28709154

Sold for a Morning Glory Data Mining Light(29 Keys)

http://backpack.tf/profiles/76561198155294524#!/compare/1484352000/1484438400

http://backpack.tf/item/671701209

25-30.

Credits to Mindacos for the suggestion. He found the proof, I'm just posting it.