My G. Ushanka suggestion was accepted within an hour of posting, lol

Sale 1

http://www.tf2outpost.com/trade/26956870 Sold for OF Stuntman + KaW L'Inspecteur + 64 ref (4 keys) http://i.imgur.com/rLdtmve.png

B/O for Dread was 24

X = 4 + 12.5*0.9 + 13.5*0.9

X = 27

X = 24 (B/O)

Stuntman http://backpack.tf/item/730567270

Dread http://backpack.tf/item/2850507323

L'inspecteur http://backpack.tf/item/1814885528

Ref + stuff https://gyazo.com/12bc7fcb2112a7319fd297f09b133c99 http://backpack.tf/profiles/76561198080179568?time=1441522800&compare=1441609200

Mini for L'

http://backpack.tf/vote/id/56109c57b98d88a524cc1bae 13.5, using 13.5

Sale 2

http://www.tf2outpost.com/trade/27106620 Sold for MN Bot Dogger + 10 keys

B/O for Dogger was 15

X = 15*0.9 + 10

X = 24

Keys https://gyazo.com/8b9f9fca867f725c7039c3f41ad7ea52 http://backpack.tf/profiles/76561198024700553?time=1443510000&compare=1443337200

Dread http://backpack.tf/item/354459640

The buyer nor seller appear on the MN Dogger history for some reason, but on Outpost history they do http://www.tf2outpost.com/item/440,4173714189,30018,5

Sale 3

http://www.tf2outpost.com/trade/26698193 Sold for 25 keys

X = 25

Keys https://gyazo.com/ff53c9987da771c7e5204ae0d339c9d0 http://backpack.tf/profiles/76561198133720914?time=1439190000&compare=1439362800

Dread http://backpack.tf/item/354459640