7 month old price. My friend used to own one of these, the hat itself was so big it covered up most of the effect. I know it looks like the one has a ton of sales in the past month but I couldn't trace anything useful out of the lot but these 4 sales should be enough.

Offered on (and sold for) a Bubbling Bonk Helm (~1.1)

http://www.tf2outpost.com/trade/18728867

Sold for 24 keys (~1.3)

http://www.tf2outpost.com/trade/18546083

Sold for 1 bud + Gifted Festive Rocket Launcher supposedly signed by QuBA, not sure how to verify if it is actually signed by them and not just someone named QuBA. I think I'll call this 1.2 solely because then I can have a sale at 1.1, 1.2, 1.3, and 1.4 and not based on any sort of actual estimation of value because I'm fairly certain this sits in the middle of the range anyways.

http://www.tf2outpost.com/trade/19632295

Sold for Orbiting Planets Tungsten Toque (~1.1) + Bills (~0.3) = ~1.4

http://www.tf2outpost.com/trade/18774777