Range is out by a lot. There is absolutely no demand for these whatsoever, and I'm mainly pricing it by the lowest that sellers will sell for in bulk.

Classifieds

http://backpack.tf/classifieds/search/965/11/0 - One selling for 3.66, lots selling at 4 ref

Unsold for 4 ref

http://www.tf2outpost.com/trade/7594200 - Unsold for 4 ref

http://www.tf2outpost.com/trade/7489079 - Unsold for 4 ref

http://www.tf2outpost.com/trade/7613817 - Unsold for 4 ref

http://www.tf2outpost.com/trade/7600497 - Unsold for 4 ref

Sold/Selling for 1 key/3.11-3.33

http://www.tf2outpost.com/trade/7348348 - Sold for 3.33

http://www.tf2outpost.com/trade/7514855 - Selling for 1 key

http://www.tf2outpost.com/trade/7453602 - Selling for 1 key

http://www.tf2outpost.com/trade/7607177 - Selling for 1 key

http://www.tf2outpost.com/trade/7567995 - Selling for 1 key

http://www.tf2outpost.com/trade/7589790 - Selling for 1 key

http://www.tf2outpost.com/trade/7618668 - Selling for 1 key

Conclusion: No-one wants one of these. I found one sold out of five pages, and there are lots selling for a key. I think a key is a good price for now.