So i went digging.

Only Sale

http://www.tf2outpost.com/trade/25647192 Sold with a White Bandanna + 3 keys for Burning Brigade + Pro KS Aussie Scat

B/O for Aviator's was 162

B/O for Brigade was 235

B/O for Scattergun was 55

X + 3 + 2.2 = 157.5*0.9 + 43.8*0.9

X = 181.2 - 3 - 2.2

X = 176

X = 162 (B/O)

Scat http://backpack.tf/item/2432572941

Assassin http://backpack.tf/item/3177520219

Brigade http://backpack.tf/item/1127123408

Stuff http://gyazo.com/abdcb9a1aefda213b8eb0368fbe34562

Mini for Scat

http://steamcommunity.com/market/listings/440/Strange Professional Killstreak Australium Scattergun Sold for $111.88 on Apr 20th

$111.88 + $111.88/1.15 = $209.17

$209.17/2 = $104.59

Keys were $2.39 on Apr 20th

$104.59/$2.39 = 43.8 keys

Another sale involved a Frostbite Kiss King, which is unpriced