Proof below. 6 month-old price. Crazily inflated, this is nowhere near 8+

Sales:

http://www.tf2outpost.com/trade/15179674

-gallon+3 buds bought burning ten gallon: http://www.tf2outpost.com/trade/14775745

-6.5 buds

http://www.tf2outpost.com/trade/14925955

-b/o of 8.5 buds

-sold for ghosts goggles+7 keys as seen in one of his offers below in current trades=~8.3 buds, probably an outlier, absolutely no offers near it

http://www.tf2outpost.com/trade/14665074

-b/o of 9 buds

-gallon+1 key+14 ref sold/bought for c9 ck: http://www.tf2outpost.com/trade/14758099

-7.3 buds (I didn't really use this in my ck suggestion)

-buyer's bp:

http://backpack.tf/id/76561198050239682?time=1380610800

http://backpack.tf/id/76561198050239682?time=1380956400

-notable offers:

roboactive honchos-1 bud=6.7

Current trades:

http://www.tf2outpost.com/trade/14373656

-b/o of 9 buds, few months old

-recent notable offers:

sulph aa+sweets=6.7+

sulph aa=6.7

cloudy billy (outdated)+smoking fez (outdated)+stormy stovepipe=6.4

burning conq=6.8

dp jefe=7.2

secret big country (very outdated)=7.2

duped burning cowl=no idea

http://www.tf2outpost.com/trade/16400057

-b/o of 9 buds

http://www.tf2outpost.com/trade/14773522

-in a set, probably not selling in a while

Sales: 6.5, 7.3, 8.3

Seeing as 8.3 is an outlier, offers also match up with the range of 6.5-7.3 so that's the range. Unusual overpay and original prices used.