First unusual suggestion.

I own one of the two unusuals, still trying to be pretty objective.

Proofs:

I myself payed a Terror Watt BoA for the Hellfire Ze Goggles + Bubbling Bear Necessities.

I value the terror watt close to 90 keys - 16 of the other hat = 74.

Now other trades:

http://www.tf2outpost.com/trade/27016345 Originally traded for a searing plasma Das Maddendoktor which is still unpriced but got offers around 90 keys.

Recently traded for this a Green Energy Tyrolean and a Screaming Tiger Results are in - Tyrolean is outdated (58 keys) + screaming results are in( recent drop to 41 keys) = 99 keys

As you can see the hat have been traded for around 85 - 90 keys, trying to be conservative I suggest 80 keys.

Feedback is always welcome.

Have a good one