just recently sold this for 21 keys

proof of sale: http://imgur.com/BCd05C2

my outpost trade: http://www.tf2outpost.com/trade/11785030

Also had an offer of bubbling HWNN that I was going to take but he sold before I could accept.

only other seller

http://www.tf2outpost.com/trade/12005862

offers around 18-19 with a 20 key b/o

such offers include

-13 keys + S.F. Axtinguisher + G. Quadwrangler + 4 ref

-19 keys (from the guy I sold to for 21)

-17 keys + tuxxy

low value based on the offers. Also appears as though the other seller is going to take the 17 keys + tuxxy offer. High value based off my own sale.