Just narrowing the range. Everybody sells for the lower range, extremely easy to find one for 1.4 keys, although 1.2 keys are more occasional.

Classifieds:

http://backpack.tf/classifieds/search/5077/6/0 4 sellers at 1.2 keys, 1 seller at 1.23, 2 sellers at 1.3 keys and one seller at 1.4

Sellers below current high range:

http://www.tf2outpost.com/trade/12203411 key + 1.88

http://www.tf2outpost.com/trade/12141586 1.3 keys

http://www.tf2outpost.com/trade/12197156 1.4 keys

http://www.tf2outpost.com/trade/11863589 1.4 keys

http://www.tf2outpost.com/trade/12009703 1.4 keys

http://www.tf2outpost.com/trade/11678624 sold out at 1.2 keys

http://www.tf2outpost.com/trade/12177750 1.4 keys

http://www.tf2outpost.com/trade/11724715 1.4 keys

http://www.tf2outpost.com/trade/11439456 1.2 keys

http://www.tf2outpost.com/trade/9693922 1.4 keys

http://www.tf2outpost.com/trade/11989624 key + 1.66

http://www.tf2outpost.com/trade/12138481 key + 1.66

http://www.tf2outpost.com/trade/12196003 key + 1.66

http://www.tf2outpost.com/trade/12195940 1 key + 1 ref (really is the lowest price on OP)

http://www.tf2outpost.com/trade/12102215 key + 1.66

Unsold for 1.5 keys: I had trouble finding unsolds BECAUSE there were so many people selling for lower. Not kidding. I hope this is enough.

http://www.tf2outpost.com/trade/12119159 2 days (young)

http://www.tf2outpost.com/trade/12018037 6 days (high end of backpack.tf price)

http://www.tf2outpost.com/trade/12045042 5 days

http://www.tf2outpost.com/trade/11962180 1 week

http://www.tf2outpost.com/trade/12082660 3 days

It's funny, now I'm finished and it's AFTER EIGHT ;D