Proof below. 3 month-old price.

This is actually an increase from the original suggested value.

Hardly any recent sales and some are impossible to track.

Sales:

http://www.tf2outpost.com/trade/15044603

-sold for 4 buds like he wanted, also seen here: http://www.tf2outpost.com/trade/15676370

-notable offers:

3.5 buds too low

http://www.tf2outpost.com/trade/15676370

-wanted 5 buds

-brigade+power surge bubble (unpriced but around 5 if I were to take a guess)+roboactive slouch (4)+7 keys in items (0.43) bought clean cloudy hwnn (13.25): http://www.tf2outpost.com/trade/14619183

-leaving this sale around 4, but I'm not using this

Current trades:

http://www.tf2outpost.com/trade/14817619

-b/o of ~4.2 buds, nearly 2 months

-notable offers:

dp brigade+ts max=4.2

misty attendant=5.1, 1 bud above seller's b/o for 2 months, obvious outlier

beams vrh=4.2

ge pyromancer+sweets=4+

http://www.tf2outpost.com/trade/15837074

-b/o of 5.5 buds, 1 week

-notable offers:

duped misty belt, unsure of value

http://www.tf2outpost.com/trade/15866558

-notable offers:

c9 brigade=4.1

Notable trades:

http://www.tf2outpost.com/trade/14434855

-one of his trades in a set

-his older trade without the set: http://www.tf2outpost.com/trade/14556973

-b/o of 4.3 buds

-notable offers:

o.f. pyromancer+g. fetti spartan+steaming degroot=4.2

4 buds accepted but fell through

Very few sales, most are old ones used in previous suggestion. Low end from some pure offers of 4 and a sale. High end is from 3 offers of 4.2. Regarding that trade with a b/o of 4.2 for 2 months, if he had accepted any of the 4.2 offers he had gotten he would have sold for his b/o. So it's not really 'unsold' since he already had people paying his b/o, just in unusuals. Very simple range from minimal proof. Unusual overpay and original prices used.