1) http://www.tf2outpost.com/trade/22977413#latest - sold for 14 keys in items 14 * 0.9 = 12.6 keys

2) http://www.tf2outpost.com/trade/22927875 - bought it for 10 keys (QS)

3) http://backpack.tf/profiles/76561198090529595?time=1412406000 => http://backpack.tf/profiles/76561198090529595?time=1412492400

Sold for Orbiting Planets Base Metal Billycock 0.9 * 15 = 13.5 keys Rounding to 13 cuz this is robo hat and seems to be outlier otherwise

4) http://www.tf2outpost.com/trade/22927406 Sold for Dead Presidents Gridiron Guardian 13.5 * 0.9 = 12.15 keys

5) http://www.tf2outpost.com/trade/22622415 - b/o was 13 (sold for Smoking Sultan's Ceremonial 0.9 * 14 = 12.6 keys