At the moment of writing, 2 available on the classified at 1 key each.

[PROOF BELOW]

Selling @ 1 key

http://www.tf2outpost.com/trade/19588786

http://www.tf2outpost.com/trade/19604139

http://www.tf2outpost.com/trade/19500630 (if you buy a strange disiplinary action with it for 3 keys, so 1 key)

http://www.tf2outpost.com/trade/19600067

http://www.tf2outpost.com/trade/19558520

http://www.tf2outpost.com/trade/19230513

Selling @ 1 key - 1 key and 2 ref

http://www.tf2outpost.com/trade/19504746 (1 key and 1,33 ref)

http://www.tf2outpost.com/trade/19367387 (1 key 1 ref (4 instock))

http://www.tf2outpost.com/trade/19072967 (1 key 1,66 ref)

Selling @ 1 key and 2 ref

http://www.tf2outpost.com/trade/19115991

http://www.tf2outpost.com/trade/19573561

http://www.tf2outpost.com/trade/19595823

http://www.tf2outpost.com/trade/19382550

http://www.tf2outpost.com/trade/19592636

http://www.tf2outpost.com/trade/19471389

Unsolds @ 1 key and 3 ref (1,4 keys)

http://www.tf2outpost.com/trade/19575086 (1 day)

http://www.tf2outpost.com/trade/19578271 (1 day)

http://www.tf2outpost.com/trade/19583435 (1 day)

http://www.tf2outpost.com/trade/19368645 (1 week)

http://www.tf2outpost.com/trade/19574779 (1 day)

http://www.tf2outpost.com/trade/19386028 (1 week)

http://www.tf2outpost.com/trade/19478612 (1 week)

and more...

Thanks for reading. Use your common sense when upvoting or downvoting this suggestion, because I'm a white belt.