Counter-suggestion.

[proof below]

Sellers/solds below 4

http://www.tf2outpost.com/trade/18562610 - 3.66 (comments)

http://www.tf2outpost.com/trade/18581061 - 3.66

http://www.tf2outpost.com/trade/18500687 - 3.66

http://www.tf2outpost.com/trade/18552121 - 3

http://www.tf2outpost.com/trade/18408851 - 3 (SOLD)

http://www.tf2outpost.com/trade/18413891 - 3.22 (SOLD)

Unsolds at 4

http://www.tf2outpost.com/trade/18496497 - 5 days

http://www.tf2outpost.com/trade/18474922 - 6 days

http://www.tf2outpost.com/trade/18480802 - 6 days

http://www.tf2outpost.com/trade/18465439 - 6 days

http://www.tf2outpost.com/trade/18361521 - 1 week

http://www.tf2outpost.com/trade/18327797 - 1 week

http://www.tf2outpost.com/trade/18453180 - 1 week (3.77)

http://www.tf2outpost.com/trade/18262750 - 2 weeks

http://www.tf2outpost.com/trade/18140556 - 3 weeks

http://backpack.tf/classifieds/search/id/52d2149d4cd7b878328b456a

Many available under 4.

Only 1 seller on TF2OP and 2 in the classifieds at 3 ref. I dont think thats is enough to set 3 ref as the low end. (Plus, some of the 3.66 and below sellers are also a bit young.)