8 month old price.

Sale 1 :

Before ; http://backpack.tf/profiles/76561198076239220?time=1430982000

After : http://backpack.tf/profiles/76561198076239220?time=1431154800

Sold for an orbiting fire guadalajara = 18 keys

Aces Guad was offered, so no overpay there

Mini of the orbiting fire guadalajara :

Before : http://backpack.tf/profiles/76561198074764837?time=1433142000

After : http://backpack.tf/profiles/76561198074764837?time=1433228400

Sold for an orbiting planets milkman = 18 keys

Sale 2 :

Before : http://backpack.tf/profiles/76561198071197720?time=1429513200

After : http://backpack.tf/profiles/76561198071197720?time=1429858800

Sold for an orbiting planets bone dome ( 13 keys ) + 4 keys in items : 17 * 0.9 = 15 keys

Sale 3 :

Before : http://backpack.tf/profiles/76561198120768380?time=1429167600

After : http://backpack.tf/profiles/76561198120768380?time=1429254000

Sold for an aussie black box :19 keys + 2 keys = 21 keys (outlier)

Sale 4 :

Before : http://backpack.tf/profiles/76561198136385861?time=1428735600

After : http://backpack.tf/profiles/76561198136385861?time=1428914102

Sold for dead president fez : 17 keys * 0.9 = 15 keys

Thx to Marty for the help :)

Thus taking a range of 15 to 18 keys