As for how much it costs, I'd call and ask. Some may charge, as someone else's answer suggests, close to $80. Others may be more lenient. You may try talking to someone in a different department, like parts. They may be willing to bend the rules if you're just looking for that code...
One last thing. If this is the radio that came with YOUR car, you should check the manual. A lot of times it's listed in there... Check it out before you do anything.How can I get the code to unlock my car radio?take it to the dealer ....they will charge u about 80 bucks.....yes it is a rip off but nothing else u can do.....