Pre owned copy of TESO PC game

Hi all,
I was in my local game exchange and I noticed that they had a second hand copy of TESO for the PC. Is there any point in buying this? Will it work or do you need a new copy with a unique code? I was under the impression that the PC version requires a code but then I can't work out why the game shop would buy and sell second hand copies. I am asking because I have some credit with them for games I have exchanged.

Cheers :)

The problem with 2nd hand ESO is that you have to log in registering your email addr. Even if you just had a login/passw if you had any problems, or wanted to buy something, you would have to use the email addr registered. Now if the person was good enough to use his email and submit an email change to ESO to your email addr, then you would have full control. But if you purchase, what guarantee would you have that it would happen? That is the prob. FYI.