Unsold at 4.5

http://www.tf2outpost.com/trade/9886385 1 week

http://www.tf2outpost.com/trade/10049085 3 days,same guy from the first link

http://www.tf2outpost.com/trade/9996811 5 days,last bump 3 days ago

http://www.tf2outpost.com/trade/10013948 5 days,last bump 3 days ago

http://www.tf2outpost.com/trade/10026151 4 days,has autobump

http://www.tf2outpost.com/trade/10092527 2 days,backpack.tf high end,has autobump

http://www.tf2outpost.com/trade/10131470 4 keys 1 ref,unsold 15 hours,has autobump

Selling at 4 keys

http://backpack.tf/classifieds/search/540/1/0 2 selling at 4 keys,1 selling at 4.5 and it's painted "after eight"

http://www.tf2outpost.com/trade/10128009 18 hours,still unsold

http://www.tf2outpost.com/trade/10056943 backpack.tf lowest price (lol you don't see this a lot),3 days,autobump and unsold

So basically,4.5 keys is not relevant. The buyers on outpost are looking to buy at 2 keys - 3.75 keys,no success.