Easily 3 keys at least. I've sold a couple for 4.

Well here's one more link since you conveniently omitted yourself... IMO it seems like a major conflict of interest for you to set a new price when you're trying to sell them:

http://www.tf2outpost.com/trade/5493970

http://tf2tp.com/trade.php?trade=8447079

Range is too big

I agree, range is too wide. 3-3.5 seems like a better range. And I tihnk you do too, as you upvoted the 3-3.5 suggestion. I'll close this then.