Did you check if any of these quick sold. Also the 1 key sale may be to old to use. And fluffy pony has been bragging about selling multiple these and quick selling them for 1.5 keys

http://www.tf2outpost.com/trade/26162700 never bumped quick sold for 1.2 keys

http://www.tf2outpost.com/trade/26035387 this sale is outdated as it sold on the 28th if you look at the comments

Buyer for 85% of bp.tf price http://www.tf2outpost.com/trade/26088214

Buyer for a key on classifieds