Proof below. Overpay calculated. Original prices used

Sales

http://backpack.tf/id/76561198009909592?time=1389513600 ---> http://backpack.tf/id/76561198009909592?time=1389686400

Lvl. 67 Max = 2.4 buds (outlier)

http://backpack.tf/id/76561198009909592?time=1384848000 ---> http://backpack.tf/id/76561198009909592?time=1385193600

Phosphorous Head Warmer = 3.3 buds

Bear's counter-proof

Hmm. Not sure

http://www.tf2outpost.com/trade/16994451

Flies Tower + DP Bonnet (bonnet is unpriced, but this is surely >3.3)

KS prancers + phos pug is well above your low end

http://www.tf2outpost.com/trade/15723956 - sold for burning topi (offered, so no overpay) - 2.8

http://www.tf2outpost.com/trade/15917776 - the guy who sold for the max had an offer of ~3 - burning bombing run

Can tell exactly whats up with the max trade, but it looks like an outlier. 2.8-3.3 sounds a bit better to me

Help / Constructive Criticism / Additional Proof / Counter-Proof is ALWAYS welcome! >;3