The skull is wearing the Beak. Other hats that look like this:

http://backpack.tf/stats/Unusual/Large%20Luchadore/Tradable/Craftable/44

http://backpack.tf/stats/Unusual/Brain%20Bucket/Tradable/Craftable/44

Sale 1:

Sold for a Time Warp Frickin' Sweet Ninja Hood

(175*0.9) = 157.5 rounding to 160 keys

http://www.tf2outpost.com/trade/26709840

http://backpack.tf/profiles/76561197982569301?time=1438930800

http://backpack.tf/profiles/76561197982569301?time=1439103600

Sale 2:

Sold for 150 keys

150 keys

http://backpack.tf/profiles/76561198056558991?time=1436857200

http://backpack.tf/profiles/76561198056558991?time=1436943600

Sale 3:

Sold with a S.F Pro KS Shotgun and 2 keys of sweets for a PE Sole Mate + a Scorching Fuka

(110 + 95)*0.9 = 184.5 rounding to 185 keys

http://backpack.tf/profiles/76561198066701092?time=1439362800

http://backpack.tf/profiles/76561198066701092?time=1439449200

Aparantly it was actually the Sole Mate and a Ghastly ninja hood, but he sold the ninja in 10 minutes so he isn’t even in the history of the ninja, and on the compare script the ninja doesn’t show up… but the ninja is unpriced and it sold for the fukaa so I am using that as the mini, which doesn’t effect the value of that sale

http://backpack.tf/stats/Unusual/Frickin'%20Sweet%20Ninja%20Hood/Tradable/Craftable/85

Sale 4:

There was also a sale for the Ghosts Haz and a Phantasm sack, but I left that sale on an open suggestion for the Ghosts Haz, so it might end up getting used to update the Ghosts Haz.

Notes:

Mini for the S.F Pro KS Shotgun: ~12

http://backpack.tf/classifieds?item=Festive+Shotgun&quality=11&tradable=1&craftable=1&killstreak_tier=3

http://i.imgur.com/tGWhYUo.png

Unsold at 12 keys for a day on classifieds

Mini for the Fuka: ~95

http://backpack.tf/vote/id/55cd27b4ba8d8819578b4575

Conclusion:

Sales at 150, 160 and 185,taking the final range at 150 to 185.