This thing is almost the same case than the bill's, why pay 15 keys for one unpainted if you can get one painted (lime, pink, ts, black...) for 14 keys? Also, most of them are part of a set or have an outdated price (like one bud..).

Selling at 14 keys or less:

Classifieds: http://i.imgur.com/L3ucFXo.png?1 (14, 14, 14, 14, 14.5 and 14.6 keys)

http://www.tf2outpost.com/trade/13469654 (13 keys, painted mint, 1 day ago)

http://www.tf2outpost.com/trade/13484585 (painted pink, 16 hours ago)

http://www.tf2outpost.com/trade/13011109 (2 weeks ago)

http://www.tf2outpost.com/trade/13480404 (painted lime, 19 hours ago)

http://www.tf2outpost.com/trade/13481138 (painted pink, 19 hours ago)

http://www.tf2outpost.com/trade/13458148 (painted team spirit, 1 day ago)

http://tf2tp.com/trade.php?trade=9694612 (painted pink, 18 hours ago)

Unsold at 15 keys:

http://www.tf2outpost.com/trade/13135138 (1 week)

http://www.tf2outpost.com/trade/13328354 (14 keys and 5 ref, painted lime, 6 days ago)

http://www.tf2outpost.com/trade/13454603 (1 day)

http://www.tf2outpost.com/trade/13501600 (painted black, new)

http://www.tf2outpost.com/trade/13339864 (painted team spirit, 5 days)

http://www.tf2outpost.com/trade/13335274 (painted grey, 5 days)

http://www.tf2outpost.com/trade/13367154 (painted lime, 4 days)

http://www.tf2outpost.com/trade/13493266 (painted black, 7 hours ago)

http://www.tf2outpost.com/trade/13486127 (painted team spirit, 15 hours ago)

http://www.tf2outpost.com/trade/13114631 (painted waterlogged, 1 week)

http://www.tf2outpost.com/trade/13437472 (painted muskel, 2 days ago)

http://www.tf2outpost.com/trade/13470887 (painted green, 1 day ago)

http://www.tf2outpost.com/trade/13356345 (5 days ago)

http://www.tf2outpost.com/trade/13333854 (painted team spirit, 5 days ago)

http://www.tf2outpost.com/trade/13291852 (1 week)

The only recent sale I have found: http://www.tf2outpost.com/trade/13471119 (14 keys and painted black).