Gadda price other hats to price other hats.

http://www.tf2outpost.com/trade/19139295 Sold for a C. Bubbles Shako ( 2.9 buds. Added the owner on this one)

http://www.tf2outpost.com/trade/19007138 Sold for Terror-watt Lid ( 2.8 buds )

http://www.tf2outpost.com/trade/18493914 Sold for Stormy Storm brigade helmet. ( 1.9 buds ) <-- Faceman calls it a outlier!

http://www.tf2outpost.com/trade/18433780 Sold for 50 keys pure ( 2.5 buds. Asked the owner on this one )

All the proof I could find. If you find more or anything comment below and I'll toss it in. Thanks!