http://backpack.tf/vote/id/52215f46ba253697178b456d - this brought up my attention.

Holy balls so many trades in sets. ಠ_ಠ No wonder why it's so easy to highball this item.

Horribly outdated, 3 week old price.

Sellers

http://www.tf2outpost.com/trade/14043108 - sold fast for 3 ref

http://www.tf2outpost.com/trade/13998579 - sold for 3.33

http://www.tf2outpost.com/trade/13877008 - sold for 3.33

http://www.tf2outpost.com/trade/8942819 - sold for 3.33, out of stock

http://www.tf2outpost.com/trade/7300323 - offered 3.44

http://www.tf2outpost.com/trade/14040558 - sold 3.66

http://www.tf2outpost.com/trade/13875031 - sold 9 for 4 ref

http://www.tf2outpost.com/trade/13999487 - sold 4 for 4 ref

http://www.tf2outpost.com/trade/13999232 - sold 4 ref

http://www.tf2outpost.com/trade/13659694 - sold at least one for 4 ref. Declined offer of 3.66.

http://www.tf2outpost.com/trade/11514758 - multiple adds for 4 ref

http://www.tf2outpost.com/trade/14030618 - sold 4 ref --> http://puu.sh/4flkx.png

http://www.tf2outpost.com/trade/13722159 - sold at least 1 for 1 key, declined offer of 3.33

http://www.tf2outpost.com/trade/8053555 - Has C/O of 2 keys and .11. Even has a comment saying that he will offer a key.

Feel free to counter/support my proof.