There ye go Heliix

Sale 1

http://www.tf2outpost.com/trade/26240103 Sold with 6 keys for Cauldron Warmer

Tree was offered on Warmer

X + 6 = 35

X = 29

Warmer http://backpack.tf/item/1242467229

Tree http://backpack.tf/item/2547446206

Keys http://gyazo.com/0c65969477fcd6bfea8d219aaf491573

Mini for Warmer

Yes yes it is only 1 month old but the B/Os indicate it needs a further drop.

http://gyazo.com/63575d4f5770cfcd4f888027d1180db6 B/Os of 39 and 31, using mid point (35 keys)

Sale 2

http://www.tf2outpost.com/trade/26046578 Sold for Blizz Country + Blizz Pith + 1 key of sweets

B/O for Tree was 33

Country and Pith had no trade, presuming offered

X = 15.5*0.9 + 13*0.9 + 1*0.9

X = 27

Pith http://backpack.tf/item/1079275601

Country http://backpack.tf/item/1079742110

Tree http://backpack.tf/item/2547446206

Sweets http://gyazo.com/24e03f52e8cfd6e5b37d8d5a1a13e87f

Mini for Country

http://backpack.tf/vote/id/559e1ae1b98d889b6e8b4695 15.5, using 15.5

Mini for Pith

http://backpack.tf/vote/id/559e207edea9e9b45f8b4716 13, using 13

Sale 3

http://www.tf2outpost.com/user/604499,2?id=3751000365 Sold for 2 keys + Searing Billycock

Had been attempting to sell for ages

Ignoring B/O on Tree

B/O for Billy was 23

X = 2 + 23*0.9

X = 23

Billy http://backpack.tf/item/197078929

Tree http://backpack.tf/item/2547446206