5 ref is too oudated. No one is even buying them for lower than 5 ref.

http://www.tf2outpost.com/trade/8624491 - Painted one for 5 ref

http://www.tf2outpost.com/trade/8501706 - key + 1.33 = 5 ref, Unsold for 6 days

http://www.tf2outpost.com/trade/8569733 - 4.66 ref Unsold for 3 days

http://www.tf2outpost.com/trade/8576197 - 5 ref b/o, unsold for 3 days

http://www.tf2outpost.com/trade/8226324 - Probably he/she's b/o is 5 ref, no one took it.

http://www.tf2outpost.com/trade/8580588 - Painted one for 4.66 (1 key + 1 ref) No takers

http://www.tf2outpost.com/trade/8066992 - 4.66 b/o, Unsold for a long time

http://www.tf2outpost.com/trade/8623308 - Another trade selling painted one for 4.66

http://www.tf2outpost.com/trade/8540665 - 5 ref b/o, Unsold for 4 days

http://www.tf2outpost.com/trade/8593282 - Firm price, Unsold.

http://www.tf2outpost.com/trade/8595886 - Selling it for 4.33 ref (1 key + 2 rec)

http://www.tf2outpost.com/trade/8231499 - Best offer he could get for 2 weeks was 1 key + 1 rec which is 4 ref.

http://www.tf2outpost.com/trade/8553814 - Selling it for 3-4 ref. Even this is unsold

As I said 5 ref is too much. Most of the people are selling it for 4.66, most of them were unsold. We can easily find painted ones for 4.66 as well which seller would sell their anger without paint for 4.33 since every paints at least worth 1 reclaimed. Could possibly find sellers for 4 ref. So 4~4.33 ref seems good range.