Carbon's name comes from the Latin "carbo", meaning "charcoal"

Sale 1

[No OP Trade] Sold for Twatt Bucket

X = 15

Bucket http://backpack.tf/item/2775605751

Elfin http://backpack.tf/item/1788281370

Trade http://backpack.tf/profiles/76561198160393042?time=1447401600&compare=1447488000

Mini for Bucket

http://backpack.tf/vote/id/5689c859dea9e9210b0dd407 15 keys, using 15

Sale 2

http://www.tf2outpost.com/trade/27171210 Sold for Smoking Batter's + 3 keys of sweets

B/O for Batter's was 16

Elfin had no trade

X = 15 + 3

X = 18

Batter's http://backpack.tf/item/1088144059

Trade http://backpack.tf/profiles/76561198004236703?time=1446102000&compare=1446361200

Elfin http://backpack.tf/item/1788281370

Mini for Batter's

http://backpack.tf/vote/id/5689da1ddea9e99d210dd40f 15 keys, using 15

Sale 3

http://www.tf2outpost.com/trade/27409677 Sold for Spec KS Aussie Amby + 1 key of sweets

X = 18 + 1

X = 19

Trade http://backpack.tf/profiles/76561197995915986?time=1447660800&compare=1447833600

Amby http://backpack.tf/item/3699653611

Elfin http://backpack.tf/item/1671610908

Mini for Amby

https://steamcompanion.com/tf2/Strange-Specialized-Killstreak-Australium-Ambassador/ Sold for $46.93 on Nov 18

46.93 + 46.93/1.15 = 87.74

87.74/2 = 43.87

Keys were $2.41 at time of sale

43.87/2.41 = 18 keys

Seller

http://www.tf2outpost.com/trade/27645696 17 keys