Well, time this hat got itself a price, it seems. All unusual offers have had overpay accounted for by using the median value, then multiplying by 0.9.

Only one being sold on outpost at the moment, in this trade: http://www.tf2outpost.com/trade/12848122

Notable offers include: Purple Energy Jumper's Jeepcap (3.1 buds), Holiday Headcase (2.8-3 buds), Level 62 Max's Head + 1 bud (3-3.2 buds), and 3.5 buds pure,

There have been two sales of this hat as well, the first being sold for a Phosphorus Grimm Hatte ( http://www.tf2outpost.com/trade/12719317 ) (3.9 buds), and the second being the one I bought for a Stormy Storm Flamboyant Flamenco, a Steaming Bonk Boy, and 15 keys (4.8 buds)

( http://www.tf2outpost.com/trade/13057530 )

Now I have set the range to be quite wide, and would definitely like some feedback on whether or not I should keep or change this range. Either way, I chose 3.5 to be the low end for that is the highest of the pure offers at the moment in time, and I set the high end to 4.3 as that is the median between the two sold values.

Again, if this needs refining, then I will gladly close and reopen this suggestion with a more accurate range.