Due the ref price ihave to repeat myself :s According to ad's on tf2op people got offers starting from 150$ through holiday headcase Sunbeams Gatsby ending on the Harvest Moon one. I think setting the price up to 4 buds is not a bad idea. Proof below

Recent offers

http://www.tf2outpost.com/trade/12315863

http://www.tf2outpost.com/trade/13844242

Sold

http://www.tf2outpost.com/trade/13249959 gifted one for holiday headcase

http://www.tf2outpost.com/trade/12879361 same gifted for headcase and sweets

http://www.tf2outpost.com/trade/14320652 sold for Miami Nights Stout Shako worth like 3.8-4.5 buds

http://www.tf2outpost.com/trade/13802943 here I'll try to ask the seller if it was 3 or 4 buds but he's rarely online

http://www.tf2outpost.com/trade/14448218 sold for green energy Ze Goggles + 1bud