I replaced my head unit yesterday and rung my local Seat dealer who would have happily charged me an £21 to retrieve my radio code. He did suggest I ring the dealer where the was originally bought from, which I did and got the code for free. YAY! So it's worth doing that before you pay for it.
I did have a few problems getting the old radio out though, so went to halfords and was helped for free to remove the old one and replace with the new one by a very nice man! Must have been Christmas cheer
, but nice when people are helpful and it's free