Thanks aaroncns!

My economic's teacher uses this site to show us an economy that isn't TOO fucked.

Sale 1

http://backpack.tf/profiles/76561198042399825?time=1429513200 Before

http://backpack.tf/profiles/76561198042399825?time=1429599600 After

Sold with S.PDA for Burning Ze Goggles + Vivid Marauder

88 x 0.9 = ~79

-7.5

= ~72

Sale 2

http://backpack.tf/profiles/76561198056342313?time=1429340400 Before

http://backpack.tf/profiles/76561198056342313?time=1429426800 After

Sold for Pro Killstreak Aussie Knife (http://steamcommunity.com/market/listings/440/Strange%20Professional%20Killstreak%20Australium%20Knife)

Sales average at $95 US

95 / 2.40 = ~40

Taking this as an outlier by recommendation.

Sale 3

http://backpack.tf/profiles/76561198048424548?time=1429167600 Before

http://backpack.tf/profiles/76561198048424548?time=1429328411 After

Sold for KaW Brotherhood of Arms

68 x 0.9 = ~61

The last sale seems invalid and will become outdated in 13 days anyway