Meh.

Sale 1

http://www.tf2outpost.com/trade/25459774 - Sold for 20 keys

Sale 2

http://www.tf2outpost.com/trade/25863773 - Sold for a Eerie Orbiting Fire Cosa Nostra Cap (38*0.9 = 34 keys) (Outlier)

Sale 3

http://www.tf2outpost.com/trade/22278961 (Don't let the date fool you, the sale happened in Sat, 02 May 2015 so it's valid) - Sold for a Blizzardy Storm Brigade Helm (15 keys) + 6 keys (15*0.9 + 6 = 19 keys)

Mini for the Blizzardy Storm Brigade Helm

http://www.tf2outpost.com/trade/25864155 - Sold for 15 keys

Feel free to counter / support my proofs