Huh.

Sold for a Purple Energy Bombing Run(26 Keys)

http://backpack.tf/profiles/76561198072382387/#!/compare/1454918400/1455004800

Sold for a Strange Festive Spec KS Minigun(~9 Keys) and 16 Keys(25 Keys total)

http://backpack.tf/profiles/76561198095320741/#!/compare/1456560000/1456646400

Seller at 20 Keys: http://www.tf2outpost.com/trade/28041201

There's another seller at 20 and a 14 day unsold at 21 on the classifieds.

Taking the low end from the 3 sellers at less, since these two sales were the only ones I could find. 20-26 Keys should be fine.

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