Well he has been trying to sell for 15 keys http://www.tf2outpost.com/trade/22752333 and http://www.tf2outpost.com/trade/22786988 .

He also mentioned not taking offers less than 12 keys so he is sort of looking for around 12 keys.

And how fast an item sells shouldn't be based on time alone.

http://forums.backpack.tf/index.php?/topic/6033-new-unusual-price-suggestion-guide-the-cheat-sheet/

What is a quicksell?

Time is only one factor used to determine a quicksell. If a hat sells within 1-2 days for its b/o in pure, one should be suspicious. However, since time to sell varies greatly among the type of hats (old vs new effects, misc vs hats, high tier vs low tier), this is not a reliable way to identify a quicksell.

More important is how a sale relates to other sales. If a hat sells for less than commonly offered values in pure or unusuals or for less than common trade points, that is likely a quicksell.

Special note on the "If a hat sells for less than commonly offered values in pure or unusuals or for less than common trade points, that is likely a quicksell." In this case, there are no offers(apart from the retracted offer on the current seller's trade http://www.tf2outpost.com/trade/23242767 which has no proof of whatsover so invalid) to prove that this is sold for less than the common trade points.

The best offer in pure is 10 keys on this trade of his http://www.tf2outpost.com/trade/22790607. So in my opinion, this shouldn't really be called a quicksale.