Proof below. 9 month-old price.

Sales:

http://www.tf2outpost.com/trade/18137521

-wanted 1 bud

-sold for 1 bud=~20 keys

http://www.tf2outpost.com/trade/18121862

-wanted 20 keys

-bought logo capotain (outdated): http://www.tf2outpost.com/trade/18063806

-~19 keys

http://www.tf2outpost.com/trade/17909596

-wanted 1 bud

-had someone willing to do 18 keys and was going to accept

http://www.tf2outpost.com/trade/17796603

-seems to have sold for o.f. stovepipe (outdated): http://www.tf2outpost.com/trade/17717009

-1 bud=~20 keys

http://www.tf2outpost.com/trade/17554438

-wanted 1 bud

-sold for 1 bud (20 keys: http://www.tf2outpost.com/trade/17781896

http://www.tf2outpost.com/trade/18278670

-wanted ~18 keys

-tricorne+4 keys+sweets bought g. fetti noir: http://www.tf2outpost.com/trade/18255467

-~18 keys as that was his price

Sales: 18, 18, 19, 20, 20, 20

Sales range from 18-20 keys. Didn't want to do 0.9-1 bud as it looks ugly.