Ahh, holidays...

Sellers for 1.1 keys:

http://www.tf2outpost.com/trade/24241595 12 hours

Sellers for 1.2 keys:

http://www.tf2outpost.com/trade/24236970 19 hours

Sellers for 1.4 keys:

http://www.tf2outpost.com/trade/24227093 1 day

http://www.tf2outpost.com/trade/24176120 5 days

http://www.tf2outpost.com/trade/24161688 6 days (badly bumped)

Unsold at 1.5 keys:

http://www.tf2outpost.com/trade/24190391 4 days

Unsold at 1.7 keys:

http://www.tf2outpost.com/trade/24218643 2 days

Unsold at 2 keys:

http://www.tf2outpost.com/trade/24232816 1 day

http://www.tf2outpost.com/trade/24209562 2 days

http://www.tf2outpost.com/trade/24173073 5 days

http://www.tf2outpost.com/trade/24147970 1 week

http://www.tf2outpost.com/trade/24060636 1 week

So, 2 keys doesn't sell any more, so does 1.5 keys, 1.4 keys seems to be the most common price next to 2 keys and everything below that is pretty young, so 1.4 keys for the price

All counter/supportive proof is welcomed