Well lets give this a try.

Sales

http://backpack.tf/profiles/76561198066808755?time=1432278000

http://backpack.tf/profiles/76561198066808755?time=1432364400

Sold for a Spec SK Force a Nature.

12*0.9 = 11 keys. Old and really low, Outlier.

FaN mini ~12 keys.

http://backpack.tf/classifieds?item=Force-A-Nature&quality=11&tradable=1&craftable=1&australium=1&killstreak_tier=2

12 key sellers in the classifieds.

~13 keys on SCM.

http://www.tf2outpost.com/trade/26385455

http://backpack.tf/profiles/76561198080732916?time=1436166000

http://backpack.tf/profiles/76561198080732916?time=1436252400

Sold for DBD Bandana ~22 keys.

22*0.9 = 20 keys. B/o of 18 keys.

Current sellers.

http://www.tf2outpost.com/trade/26297144 - 23 keys.

http://www.tf2outpost.com/trade/26194778 - 23 key b/o.

http://www.tf2outpost.com/trade/26398935 - 20 key b/o. Declined 16 key unusual.

2 years outdated, only 1 reasonable sale even if it did sell fast it fits in between offers and b/o's.

Couldn't find any other valid sales.