I have a friend that wants to sell her Nano. Its a 4gig and she has a case for it, and will include a FM transmitter also. She said the FM deal is 80 on its own, and she would give me all of it for 170. Does that sound like a good deal? Is there anything I should look for to make sure it works ok? Any issues with these? I remember hearing the screen scratched or something. Does the warranty remain active if you aren't the original buyer?