Hmm

Sale 1

http://www.tf2outpost.com/trade/22870609 - Sold for 1 bud + Smoking Prince Tavish's Crown (1.4 buds) (1 + 1.4*0.9 = 2.3 buds)

Sale 2

http://www.tf2outpost.com/trade/22907569 - Sold for a Terror-Watt El Jefe (3.4*0.9 = 3.1 buds) (Outlier)

Sale 3

http://www.tf2outpost.com/trade/22521686 - Sold for 38 keys = 2.4 buds

Sale 4

http://www.tf2outpost.com/trade/22265417 - Sold for a Holy Grail Taunt: Deep Fried Desire (2.9*0.9 = 2.6 buds)

Sale 5

http://www.tf2outpost.com/trade/22520230 - QS for 2 buds

Sale 6

http://www.tf2outpost.com/trade/23201790 - Sold for a Miami Nights Noble Nickel Amassment of Hats (2.1*0.9 = 1.9 buds) (Outlier because 2-bud is QS)

Sellers

http://www.tf2outpost.com/trade/22329490 - 2.2 buds (declined 2.2-bud offer before)

http://www.tf2outpost.com/trade/22318373 - 2.3 buds

http://www.tf2outpost.com/trade/22729869 - 2.4 buds

Feel free to counter / support my proofs