Well, looks like it's getting pretty hard to sell this thing for 3 keys.

Selling for 3:

http://www.tf2outpost.com/trade/11023788 (I realize the trade is only a few hours old)

Lots of people like that above ^, so moving on to older trades

http://www.tf2outpost.com/trade/10705533 this guy had an offer of 3 a week ago

http://www.tf2outpost.com/trade/10967627 selling for 3 robokeys, I guess we'll assume it's the same as 3 normal ones

http://www.tf2outpost.com/trade/10968712

http://www.tf2outpost.com/trade/10970079

http://www.tf2outpost.com/trade/10845700

http://www.tf2outpost.com/trade/10898125

http://www.tf2outpost.com/trade/10998015

http://www.tf2outpost.com/trade/11035139

http://www.tf2outpost.com/trade/10956379

http://www.tf2outpost.com/trade/11013158

http://www.tf2outpost.com/trade/10865472 (this guy can't spell)

http://www.tf2outpost.com/trade/11019817 this guy is selling for 2.5 :D

http://www.tf2outpost.com/trade/10999754

http://www.tf2outpost.com/trade/11028357 this guy wants high-end prices

http://www.tf2outpost.com/trade/10956687

http://www.tf2outpost.com/trade/10994899

http://www.tf2outpost.com/trade/10940043

http://www.tf2outpost.com/trade/10860588

http://www.tf2outpost.com/trade/11018925

http://www.tf2outpost.com/trade/10983223

http://www.tf2outpost.com/trade/11006798

I could scrape together a few more if you wanted, so please, just ask if you want more proof! And forgive me if I listed one of them twice.