3.44-3.77 is better in my opinion. I couldn't find any being sold for 3.33 ref on oupost even though I clicked the majority. And I saw a couple of trades with offers above your suggested 3.66.

Here are some things people offered:

http://www.tf2outpost.com/trade/10647232 - 4.66 (?)

http://www.tf2outpost.com/trade/6840147 - 4 ref (1week)

http://www.tf2outpost.com/trade/10718633 - 3.88

http://www.tf2outpost.com/trade/10462651 - 3.66 and 3.88

http://www.tf2outpost.com/trade/10751881 - 3.66

http://www.tf2outpost.com/trade/10634709 - 3.66

http://www.tf2outpost.com/trade/9830898 - 3.66 (1 week)

http://www.tf2outpost.com/trade/10658092 - 3.66

http://www.tf2outpost.com/trade/10635936 - 3.66

http://www.tf2outpost.com/trade/10730521 - Dirty troublemaker + dirty champ stamp (4ref-)

http://www.tf2outpost.com/trade/10575587 - 3.77 and other

http://www.tf2outpost.com/trade/8129462 - 3 ref and birdcage

http://www.tf2outpost.com/trade/10747405 - 3.55(s)

http://www.tf2outpost.com/trade/10782362 - 3.44(s)

http://www.tf2outpost.com/trade/10789548 - 3.66(s)

http://www.tf2outpost.com/trade/10785070 - 3.66(s)