1 of 1 in existence!

Sale 1:

Sold for 45 keys + Misty Skull Swagman's Swatter* (~53) + Atomic Universal Translator (16.5) = 114.5 keys (B/O caps it at 100 keys)

http://www.tf2outpost.com/trade/27995754

http://backpack.tf/profiles/76561198031371895/#!/compare/1459036800/1459123200

http://backpack.tf/profiles/76561198107969615/#!/compare/1459036800/1459123200

Mini-suggestion for Misty Skull Swagman's Swatter*:

http://www.tf2outpost.com/trade/27845091 - Declined an offer of 53 keys

~ Probably worth slightly more but 53 keys can be used as a minimum value here.

Notes:

Only recent sale in the past few months as well as there only being one in existence.

The current owner has no intentions of reselling the hat any time soon.

http://www.tf2outpost.com/trade/27734178 - missed out on an offer of 95 CS:GO keys... :(

https://i.imgur.com/7ZiWCvR.png - missed out on another offer of p.fetti rack + spec max's head + sweets :(

Conclusion:

One valid sale at 100 keys. Taking a final flat price of 100 keys.

Feel free to support/counter my suggestion!