People are selling for less than 18 keys now and the most anybody will offer is 17 keys.

http://www.tf2outpost.com/trade/9370883 - selling for 17 keys

http://www.tf2outpost.com/trade/9352364 - Selling for V.Luger + 7 keys (17-18 keys)

http://www.tf2outpost.com/trade/9328534 - 16 keys

http://www.tf2outpost.com/trade/9291748 - multiple sellers for 15 keys

http://www.tf2outpost.com/trade/9346186 - add for 15 keys

http://backpack.tf/classifieds/search/sound - Currently has a seller for 17 keys

http://www.tf2outpost.com/trade/9264088 - Best offer is 17 keys

http://www.tf2outpost.com/trade/9341676 - Best offer is 17 keys

http://www.tf2outpost.com/trade/9273549 - Best offer is 17 keys

http://www.tf2outpost.com/trade/9265350 - Best offer is 15 keys

http://www.tf2outpost.com/trade/9317905 - Best offer is 17 keys

http://www.tf2outpost.com/trade/9300846 - Best offer is 17 keys

http://www.tf2outpost.com/trade/9354697 - Best offer is 16 keys

Ass you can see it sells on the low end of 15 keys and sells at the high end of 17 keys. All anybody is willing to offer is 17 keys as well.