Before you ask, yes, I have one. It's the reason I looked into this. This price is outdated anyways. Now, I've noticed that there are LOADS of trades trying to buy these at 3 Keys, and only a few are successful. While I don't see owners accepting offers of higher, they certainly aren't selling for their own prices. Now that my background ramble is complete, here's some proof:

Sellers at 3 Keys:

http://www.tf2outpost.com/trade/8951123

http://www.tf2outpost.com/trade/8846547

Sellers at 3-4 Keys:

http://www.tf2outpost.com/trade/9196768

Sellers at 4 Keys:

http://www.tf2outpost.com/trade/9213146

http://www.tf2outpost.com/trade/8120894

http://www.tf2outpost.com/trade/9203462

http://www.tf2outpost.com/trade/9289022

http://www.tf2outpost.com/trade/9120496

http://www.tf2outpost.com/trade/8863365

SUCCESSFUL Sellers at 4+ Keys:

http://www.tf2outpost.com/trade/6075106

http://www.tf2outpost.com/trade/8591898

http://www.tf2outpost.com/trade/5569560

http://www.tf2outpost.com/trade/7540194

Unsuccessful Buyers at 3 Keys:

http://www.tf2outpost.com/trade/9293214

http://www.tf2outpost.com/trade/9231664

http://www.tf2outpost.com/trade/8771314

Successful Buyers at 3 Keys:

http://www.tf2outpost.com/trade/8719619

http://www.tf2outpost.com/trade/2214885

Buyers at 4 Keys:

http://www.tf2outpost.com/trade/9283062