I had this ready to go, then I passed out, nice

Sale 1 POSSIBLE BULK

http://backpack.tf/profiles/76561198086895780?time=1449561600&compare=1449216000 Sold for Glory Cranium, Best used to price Cranium

Sale 2

http://www.tf2outpost.com/trade/27517533 Sold for Spec KS Aussie Minigun

Dragon had no trade, presuming offered

X = 22

Mini http://backpack.tf/item/4252540617

Dragon http://backpack.tf/item/3341098265

Mini for Mini

http://steamcommunity.com/market/listings/440/Strange%20Specialized%20Killstreak%20Australium%20Minigun Sold for $57.20 and $57 on Dec 5th

Basically that's $57.10 average, no brainer

57.1 + 57.1/1.15 = 106.75

106.75/2 = 53.38

Keys were $2.41 at time of sale

53.38/2.41 = 22.2 keys

Sale 3

http://www.tf2outpost.com/trade/27205747 Sold for DP Defiant + 2 keys of sweets

B/O for Dragon was 19

Defiant had no trade, presuming offered

X = 18*0.9 + 2*0.9

X = 18

Defiant http://backpack.tf/item/2172324357

Dragon http://backpack.tf/item/3341098265

Mini for Defiant

http://backpack.tf/vote/id/566a77f0ba8d88ca19a94cc1 18 keys, using 18

Sale 4

http://www.tf2outpost.com/trade/27149973 Sold for C9 Billy

B/O for Billy was 25

X = 20.5*0.9

X = 18

Billy http://backpack.tf/item/2172270959

Dragon http://backpack.tf/item/3341098265

Mini for Billy

http://backpack.tf/vote/id/566aba7bba8d887a19a94caf 20.5 keys, using 20.5

Seller

http://www.tf2outpost.com/trade/27327406 22 keys