7 months old price.

Sales :

http://backpack.tf/profiles/76561198121994717?time=1421222400 - before

http://backpack.tf/profiles/76561198121994717?time=1421308800 - after

Sold for a pro ks collector's golf club (~7.5 keys) + strange spec ks crossbow (~1.5 keys).

A total of ~9 keys.

http://backpack.tf/profiles/76561198023033898?time=1422259200 - before

http://backpack.tf/profiles/76561198023033898?time=1422518400 - after

Sold for a spec ks diamond medi gun (~4.5 keys) + a few stranges and hats (~0.5 keys).

A total of 5 keys, outlier.

http://backpack.tf/profiles/76561198056725900?time=1425456000 - before

http://backpack.tf/profiles/76561198056725900?time=1425715200 - after

Sold for a strange ks carbonado scatter with parts (~ 5.5 keys) + painted EA (~1.5 keys).

A total of 7 keys, outlier.

Current trades :

http://www.tf2outpost.com/trade/25326359 - B/O 11 keys

Conclusion :

Suprisingly this hat is somewhat rare. Only 2 on market,1 is gifted. I've managed to find some sales, but some of them were really low. Perhaps the buyers overvalued the ks weapons. In any case, I've taken the useable sale and then current buyout to set the range.