This is my 2nd suggestion so go soft on me

Proof:

http://www.tf2outpost.com/trade/20464873 3keys (week old)

http://www.tf2outpost.com/trade/20779326 3keys (day old) this is my own trade

http://www.tf2outpost.com/trade/20804289 2.5keys (2 hour old)

http://www.tf2outpost.com/trade/20777597 3.5keys (20 hour old)

http://www.tf2outpost.com/trade/20756403 3.5keys (1 day old)

http://www.tf2outpost.com/trade/20284732 3.5keys (2 weeks old)

http://www.tf2outpost.com/trade/20732847 3.6keys (2 days old)

http://www.tf2outpost.com/trade/20748422 3keys (1 day old)

http://www.tf2outpost.com/trade/20747961 3keys (1 day old) has a killstreak on it

http://www.tf2outpost.com/trade/20736100 3keys (2days old)

http://www.tf2outpost.com/trade/20736073 3.6keys (2days old) has a strange part on it

http://www.tf2outpost.com/trade/20761520 4keys (1day old) has a strange part and killstreak on it