So I already have a 32gB 3GS and I just came across a really good deal a 3gs 32GB iPhone for sale black used but mint condition for 360.00. I already have someone that will buy it for 450 casht that's the only reason why I would buy it. What should I check out before I purchase it to make sure everythings running okay. Should I plug it into my macbook to see if it syncs. Or should a full restore just do fine? I just don't want to buy it then something is internally wrong with it.