Counter suggestion with more proof:

[url]http://www.tf2outpost.com/trade/12346771[/url] Rejected 3.66 ref

[url]http://www.tf2outpost.com/trade/13873177[/url] Rejected many 3.33 ref offer

[url]http://www.tf2outpost.com/trade/12668665[/url] Rejected 3.33 ref offer

[url]http://www.tf2outpost.com/trade/13771032[/url] Rejected many 3.33 ref offer

[url]http://www.tf2outpost.com/trade/13839635[/url] Rejected 3.33 and 3.66 ref offer

[url]http://www.tf2outpost.com/trade/14395391[/url] Rejected 3.55 ref offer

High end:

[url]http://www.tf2outpost.com/trade/14390382[/url] 4.33 ref offer

[url]http://www.tf2outpost.com/trade/14481411[/url] Sold for 4 ref

[url]http://www.tf2outpost.com/trade/10045127[/url] Sold for 4.66 ref

[url]http://www.tf2outpost.com/trade/9558470[/url] 5 ref offer

[url]http://www.tf2outpost.com/trade/11078837[/url] 4.66 ref offer

[url]http://www.tf2outpost.com/trade/14150646[/url] Sold for 5.33 ref

[url]http://www.tf2outpost.com/trade/13771032[/url] 4.33 ref offer

[url]http://www.tf2outpost.com/trade/14162971[/url] 1 add at 1 key

[url]http://www.tf2outpost.com/trade/14303922[/url] Sold for 4 ref (item history)

So i took the mean price for the high-end 4.33 ref.

Low end:

[url]http://www.tf2outpost.com/trade/14456304[/url] Seller at 3.66 ref.

[url]http://www.tf2outpost.com/search/153141853[/url] Seller at 3.66 ref

One seller at 3.66 on classifieds.