Being a new item and all,it's been really hard to price, and there are not too many solds that can easily be found (There are over 15 Outpost pages!) among the heaps of for sales, but based on the ones I could find, I think this is an appropriate starting range.

Recent sold:

http://www.tf2outpost.com/trade/22860641 Sold for 2

http://www.tf2outpost.com/trade/22862331 Sold at 2.33

http://www.tf2outpost.com/trade/22837226 Sold 2 at 2.33

http://www.tf2outpost.com/trade/22828764 Sold for 2.33

http://www.tf2outpost.com/trade/22833668 Sold for 2.33

http://www.tf2outpost.com/trade/22836677 Sold at 3

http://www.tf2outpost.com/trade/22839709 Sold for 3

http://www.tf2outpost.com/trade/22821716 Sold for 4 (First release day sale)

http://www.tf2outpost.com/trade/22836377 (Bought with another basically even value hat for a key and one ref, and assuming a key is about 8 ref, the hat was basically sold for 4.5~ ref, outlier)

http://www.tf2outpost.com/trade/22821799 Sold at 6.33!!! (Outlier much lol)

This seems to be the general selling range (.66 puting in account the outliers and the 3 prices) so far.