counter-suggestion

Sale #1 (outdated):

http://www.tf2outpost.com/item/440,2990726528,395,5 > http://www.tf2outpost.com/item/440,2990726547,174,5 - smoking whoope (17 * 0.9)~ 15 keys

Sale #2:

http://www.tf2outpost.com/item/440,2987499556,395,5 > http://www.tf2outpost.com/item/440,2974573108,478,5 - DP coppers (18 * 0.9)~ 16 keys

Sale #3(outdated):

http://www.tf2outpost.com/trade/22350575 - offered on smoking gonzilla. ~15 keys

Sale #4:

http://prntscr.com/4mctjq http://prntscr.com/4mctsc - sold with strange shotgun for Blizzardy Storm Rimmed Raincatcher. considring something was added to the fuka = no overpay(logical assumption). ~ 15.5~ 16 keys

Sale #5(sold quick)

http://www.tf2outpost.com/trade/22705326 - added 4 keys for a bud ~13

Proof to further provide 13 is an outlier/quicksell:

http://www.tf2outpost.com/trade/19191108 - quickbuyer for 13

http://www.tf2outpost.com/trade/21798255 - quickbuyer for 13

http://www.tf2outpost.com/trade/22735844 - declined 13 keys

summary:

13 is obviously a quicksell. with 2 quickbuyers,the one above sold in 1 day,and a declined offer of 13

2 sales at 16

15 sales are outdated,but can further help that 13 is an outlier