http://backpack.tf/vote/id/515a5aa64bd7b8b002000005 - proof is here, was told this is a better range

I decided I might as well put proof here too because I screwed up all the links T_T

http://backpack.tf/classifieds/search/307/11/0 - two sellers for less than 13 keys

http://www.tf2outpost.com/trade/9734496 - Selling for 12 keys, only been up for a day (Also has it up in the classified ads)

http://www.tf2outpost.com/trade/9616454 - 13 keys for 5 days, two people added or offered 13 keys, but apparently never sold

http://www.tf2outpost.com/trade/9616372 - a bunch for 13, only one person added

http://www.tf2outpost.com/trade/8587826 - sold for 13

http://tf2tp.com/trade.php?trade=9300365 - was selling at 12 keys+1 ref, is closed now

Really hard to find any serious buyers who are not trying to quick buy, can find some people buying at 11, not many above that

http://www.tf2outpost.com/trade/5051333 - many offers around the 12-13 keys range

http://www.tf2outpost.com/trade/9775404 - seller at 12 keys and 2 ref

Conclusion, not incredibly hard to sell at 13, just need some patience, but also not impossible to get one at 12.