Last mask with an incorrect price. I'll try to fix it. See proof below.

There are some completed sales for 2 scrap and some unsuccessfull buyers at 1 scrap, but also still possible to buy it at 0.11. Most sellers are trying to sell it only as a part of the set and has no offers (such trades aren't listed here).

Sold / Willing buyers / Accepted offers:

http://www.tf2outpost.com/trade/10027007 - sold few sets at 4 ref each (0.44 each mask)

http://www.tf2outpost.com/trade/11169692 - bought for 0.22

http://www.tf2outpost.com/trade/11104316 - sold for 0.11

http://www.tf2outpost.com/trade/11213963 - sold for 0.11

http://www.tf2outpost.com/trade/11271622 - 0.11 accepted

Buyers:

http://www.tf2outpost.com/trade/10779194 - 0.11, 2 weeks, no takers

http://www.tf2outpost.com/trade/11110453 - 0.11, 1 week, no takers