People Selling (for legitimate prices):

Set prices (in ascending value):

http://www.tf2outpost.com/trade/7873947 - Asking for a key, unsold after 5 days.

http://www.tf2outpost.com/trade/7723120 - Asking for 4 ref, unsold after a week.

http://www.tf2outpost.com/trade/7712486 - Asking for 4.33, unsold after a week.

http://www.tf2outpost.com/trade/5850543 - After 2 months, only 2 known sales for 4.44.

http://www.tf2outpost.com/trade/7601197 - Asking for a key + a ref, unsold after 2 weeks

http://www.tf2outpost.com/trade/7748023 - Asking for a key + 1.66, unsold after over a week.

http://www.tf2outpost.com/trade/7858472 - Asking for full price (1.4 keys), unsold after 5 days.

http://www.tf2outpost.com/trade/7833749 - Set b/o at 1.5 keys, 6 days later no offers.

http://www.tf2outpost.com/trade/7847934 - Asking for a key + 2 ref, unsold after 6 days.

http://www.tf2outpost.com/trade/7837945 - Looking for 1.5 keys, unsold after 6 days.

Looking for offers (in ascending time):

http://www.tf2outpost.com/trade/7900865 - 4 days later, 1 rejected offer for 3 ref.

http://www.tf2outpost.com/trade/7901207 - 4 Days later, no offers.

http://www.tf2outpost.com/trade/7856448 - 5 Days later, no offers.

http://www.tf2outpost.com/trade/7306699 - 3 Weeks later, no offers.

http://www.tf2outpost.com/trade/7765711 - 1 Week later, 1 rejected offer for 4 ref.

http://www.tf2outpost.com/trade/7802817 - 1 Week later, no offers.

http://www.tf2outpost.com/trade/7782951 - 1 Week later, no offers.

http://www.tf2outpost.com/trade/7386307 - 3 weeks later, one rejected offer for a key.

http://www.tf2outpost.com/trade/7375443 - 3 Weeks later, no offers.

http://www.tf2outpost.com/trade/7382144 - 3 Weeks later, no offers.

http://www.tf2outpost.com/trade/7205963 - 4 Weeks later, no offers.

The ONE exception:

http://www.tf2outpost.com/trade/7974554 - 4 hours after posting, sold for 5 ref.

People buying (by ascending price):

http://www.tf2outpost.com/trade/7785290 - Paying 2 ref, no sellers after a week.

http://www.tf2outpost.com/trade/7852402 - Paying 2 ref, no sellers after 6 days.

http://www.tf2outpost.com/trade/7086009 - Paying 2 ref, no sellers after a month.

http://www.tf2outpost.com/trade/7807518 - Paying 3 ref, no sellers after a week

http://www.tf2outpost.com/trade/7910004 - Paying less than 4 ref, no sellers after 3 days.

http://www.tf2outpost.com/trade/7070759 - Looking for offers; rejected one for a key + a ref.

http://www.tf2outpost.com/trade/7206850 - Reverse auction, c/o is key + 2 ref, too high for him.

In conclusion, I had some trouble deciding what to suggest the price for this; there are no successful buyers as there is only one page of them, and there are only 2 successful sellers after months of waiting. This is just a low-demand vintage that doesn't have very many buyers/sellers, however they both seem to generally stay away from one price; a key. I did not find any sales for a key, most likely whichever ads with that price eventually got results and were therefore closed.

http://www.tf2outpost.com/trade/7983208

This is my ad for buying one, and someone offered to sell it to me for a key.

http://www.tf2outpost.com/trade/7503717

This was the only trade I could find where a buyer got one, and the listed price was a key. He has one in his inventory.