4 months old price

To start you off,

Sellers

http://www.tf2outpost.com/trade/22992905 - 5.5 B/O, 1 week

http://www.tf2outpost.com/trade/22984298 - 5.7 B/O, 1 week

Sales

http://www.tf2outpost.com/trade/22955289 - sold for aces beak ~4.9*0.9 = ~4.4 ( http://www.tf2outpost.com/trade/22969313 )

http://www.tf2outpost.com/trade/23080306 - sold for clean max ~3.3 + DP bonk boy ~3.7 ( http://backpack.tf/profiles/76561198057434080?time=1412924400 ) - bonk boy seems to be outdated a bit, but anyway B/O at 5

http://www.tf2outpost.com/trade/23093039 - sold for 2 buds pure + spec aussie grenade launcher ~1.7 + stormy towering pillar of hats ~2.8 = 2 + 4.5*0.9 = ~6

http://www.tf2outpost.com/trade/22906159 - sold for scorching chieftains ~6.45, but B/O at 5( http://backpack.tf/profiles/76561198077959348?time=1412060400 )

Not including 6 in the range due to the current sellers.