I feel like an item is cool, so it should be worth more!

People who are selling don't qualify as proof UNLESS the item they're selling has sold. At the time I am posting this, I see all the classifieds listed at 2.5 keys or below. http://backpack.tf/classifieds/search/id/52d1c7824cd7b8d9118b4567

If that's not enough, here's some counter proof for 2.5 keys.

Sellers for 2.5:

http://www.tf2outpost.com/trade/17591447

http://www.tf2outpost.com/trade/17856263

http://www.tf2outpost.com/trade/17561459

http://www.tf2outpost.com/trade/17814803

http://www.tf2outpost.com/trade/17847995

http://www.tf2outpost.com/trade/17583898

http://www.tf2outpost.com/trade/17867491

http://www.tf2outpost.com/trade/17179342 (Wants 3 keys, but will provide 4 refined change)

Downvote.