YUP, I've certainly seen some hats sell for twice their original value for this reason. I was working on another suggestion similar to this and I'm considering going with the lower values on that, but it has other reasons.

I wouldn't have much problem pricing this around 45 keys if it weren't for the sale at 83 keys and how quickly this sold around 45 keys (which are the most recent sales). If there's any strong difference in values, just go with the most recent sales. :P I'm sure the guy who bought this for a Frostbite Cannonball wouldn't be very pleased with excluding their sale from the price, but perhaps they did overpay a bit much when they could've gotten it a month ago for half of what they paid.

There's another sale (which I looked at and isn't usable for 2 reasons) that is closer to 83 keys:

Sold for a duped Burning Stout Shako (~62 keys) + Specialized Australium Black Box (20 keys)

http://backpack.tf/profiles/76561198066881257?time=1429513200 (April 20th)

http://backpack.tf/profiles/76561198066881257?time=1429686000 (April 22nd)

(62 + 20) * 0.9 = 74 keys