This scarf does not sell at 6 keys. This is a slight drop, seeing as there is neither a huge demand nor a lot of supply. A range will stimulate the market.

Sellers selling for less than 6 keys:

http://www.tf2outpost.com/trade/11571727 - Asking for 5 keys, 5 ref

http://www.tf2outpost.com/trade/11830545 - 5.5 keys

Highest buyers in backpack.tf:

Obviously quickbuyers are not to be considered in the price range, but if buyers are successful, it is probably necessary to consider a drop in price.

http://www.tf2outpost.com/trade/10827907 - Buying for 5.4 keys. Best price.

Trades for observation (basically to see if they ever sell):

http://www.tf2outpost.com/trade/11856101 - Around 6 keys

http://www.tf2outpost.com/trade/11775610 - 6 keys (3 days ago)

http://www.tf2outpost.com/trade/11865864 - 6 keys

http://www.tf2outpost.com/trade/11801340 - 6 keys

http://www.tf2outpost.com/trade/11743832 - 6 keys, 1 offer of 5

http://www.tf2outpost.com/trade/11869383 - 6 keys

In the Classifieds there isn't a lot to see, basically a repost of a trade I saw in Outpost, selling for 5.6, and a 6 key trade. Putting here for observation.

http://backpack.tf/classifieds/search/Genuine%20Merc%27s%20Pride%20Scarf