Doing this for another suggestion, feel free to counter suggest. I'd love for this to be higher since I do dearly love the other hat and I don't want it to be going for too little.

2.5 buds

http://www.tf2outpost.com/trade/18369177

1 bud + 21 keys = 2.05 buds

http://www.tf2outpost.com/trade/18694562

Offered on (and sold for) a kill-a-watt beret(~2.4, 8 month old price but see mini suggestion) and 6 keys = ~2.1 buds

http://www.tf2outpost.com/trade/17570697

Mini suggestion for kill-a-watt beret:

Assuming overpay on a Miami Nights Ol'Snaggletooth (~2.4, 3 month old price and was not outdated at time of sale) since I can't tell for sure who contacted who first but even without the overpay this would still be keeping the kill-a-watt beret sale in the suggested range.

http://www.tf2outpost.com/trade/18225352