Proof below. 5 month-old price.

Sales:

http://www.tf2outpost.com/trade/15665021

-wanted 6 buds

-bought vivid kabuto (outdated)+sweets: http://www.tf2outpost.com/trade/15617644 + http://www.tf2outpost.com/trade/15690998

-3.8 buds clear outlier

http://www.tf2outpost.com/trade/15332820

-sold for 5 buds

http://www.tf2outpost.com/trade/17237045

-stash+10 keys ( http://www.tf2outpost.com/trade/17184197 ) bought ghosts stash

-seller's bp:

http://backpack.tf/id/76561198054504026?time=1389945600

http://backpack.tf/id/76561198054504026?time=1390032000

-~5.3 buds

http://www.tf2outpost.com/trade/16289125

-wanted 5.5 buds

-seems to have sold for miami spartan+c9 fr-o (unpriced)+vivid football: http://www.tf2outpost.com/trade/17237057

http://www.tf2outpost.com/trade/16207006

-b/o of 5.5 buds

-stash+bubbling kabuto+vivid pith (1.2 very outdated)+2 buds ( http://www.tf2outpost.com/trade/16289125 ) bought clean ge beak (10.9 slightly outdated): http://www.tf2outpost.com/trade/15815657

-seller's bp:

http://backpack.tf/id/76561198010744735?time=1386489600

http://backpack.tf/id/76561198010744735?time=1386576000

-big and complicated sale so not using

Current trades:

http://www.tf2outpost.com/trade/17236659

-b/o of 5.5 buds, almost a month

-notable offers:

c9 l'inspecteur+blizz phantom (both slightly outdated)+6 keys=4.9

gbh hw=5.2

Sales: 3.8, 5, 5.3

Not many sales so a range just with 5-5.3 sales. 1 or 2 offers within this.