What....I have no idea how Peasant's suggestion was accepted with 5 links of "proof" but anyway: PROOF:

http://backpack.tf/classifieds/search/654/6/0 3 for 2.5 keys

http://www.tf2outpost.com/trade/9508239 Has 6 (!) for 2.5 keys each :PPP

http://www.tf2outpost.com/trade/9505686 2.5

http://www.tf2outpost.com/trade/9186743 2.5

http://www.tf2outpost.com/trade/9441040 2.5

http://www.tf2outpost.com/trade/9449176 2.5

Unsold for 3 keys:

http://www.tf2outpost.com/trade/9484185

http://www.tf2outpost.com/trade/8249855 Has 2; 1 month old

http://www.tf2outpost.com/trade/9379658 5 days

http://www.tf2outpost.com/trade/7538882

http://www.tf2outpost.com/trade/9257644 1 week

http://www.tf2outpost.com/trade/8567893 1 month! co only 2.5 and even retracted

http://www.tf2outpost.com/trade/9509707

It's not hard to get for 2.5 at all.

But after all 2.5 seems to be working better than 2-2.5.

And look at this...I have 1...because I couldn't sell for 2.5 LOL

And oh my god change the currency choosing system...I messed it up again >.< 2 times! ;_;