Might be a tad too early to price this, but let's see how this will go.

Sold for 1 key:

http://www.tf2outpost.com/trade/14526533

http://www.tf2outpost.com/trade/14521761

http://www.tf2outpost.com/trade/14517838

http://www.tf2outpost.com/trade/14515593

http://www.tf2outpost.com/trade/14514183

http://www.tf2outpost.com/trade/14514280

http://www.tf2outpost.com/trade/14513994

http://www.tf2outpost.com/trade/14512694

http://www.tf2outpost.com/trade/14512135

http://www.tf2outpost.com/trade/14510430

http://www.tf2outpost.com/trade/14506899

http://www.tf2outpost.com/trade/14506959

http://www.tf2outpost.com/trade/14509582

http://www.tf2outpost.com/trade/14505253

http://www.tf2outpost.com/trade/14501733 - Sold two!

Unsold for 2 keys:

http://www.tf2outpost.com/trade/14527985

http://www.tf2outpost.com/trade/14521325

http://www.tf2outpost.com/trade/14518542

http://www.tf2outpost.com/trade/14515734

http://www.tf2outpost.com/trade/14517899

http://www.tf2outpost.com/trade/14510824 - Trade closed but not sold according to the history

http://www.tf2outpost.com/trade/14506815

http://www.tf2outpost.com/trade/14502374 - 1.5 keys!

I was thinking of pricing this at 1-2 keys at first, but then I noticed that several of these were unsold for 2 keys and the market price is below 1 key as well. I do know that the Steam Market does not count, but it would be wrong to price an item at double the price you could get it for money.

If there's something wrong in this suggestion, please let me know, I can close this if it is too early for that.