Valve I don't even know anymore.

Let's see if I can get 3 accepted suggestions in a row. :3

Classifieds

7x @ 4 keys

1x @ 2.5 keys

1x @ 5 keys

Sellers at 4 keys

http://www.tf2outpost.com/trade/24099312

http://www.tf2outpost.com/trade/24105670

http://www.tf2outpost.com/trade/24109684

http://www.tf2outpost.com/trade/24087784

http://www.tf2outpost.com/trade/24104412

http://www.tf2outpost.com/trade/24108296

http://www.tf2outpost.com/trade/24107487 - Trading for a Pool Party taunt. (4 keys)

http://www.tf2outpost.com/trade/24105858

http://www.tf2outpost.com/trade/24098055

http://www.tf2outpost.com/trade/24090427

http://www.tf2outpost.com/trade/24105227

http://www.tf2outpost.com/trade/24064456 - Old

Unsolds at 5 keys (or anything within the range)

http://www.tf2outpost.com/trade/24063395

http://www.tf2outpost.com/trade/24095828

http://www.tf2outpost.com/trade/24109623

http://www.tf2outpost.com/trade/24089088

http://www.tf2outpost.com/trade/24060589

http://www.tf2outpost.com/trade/24087121

http://www.tf2outpost.com/trade/24092737

http://www.tf2outpost.com/trade/24090515

http://www.tf2outpost.com/trade/24069815 - Old

Sellers for under 4 keys

http://www.tf2outpost.com/trade/24100831

http://www.tf2outpost.com/trade/24100736

http://www.tf2outpost.com/trade/24105919

Conclusion

4 keys is the most common price for this item. A range isn't necessary. There are too many sellers at 4 keys for 5 keys to be relevant.

Support/counter-proof is always encouraged. Thanks! ^-^