A:Answer From my personal standpoint, I had a phone on a contract for 2 years and got bored with it. So, once I payed it off, I upgraded to a phone I thought was worth the specials Best Buy was running. I purchases the phone in full, which if you want to avoid a monthly phone payment, then it's better to buy the phone outright. It's probably wise to upgrade than add a line, unless you have people who you don't mind sharing an account with, then you can get into one of their line bundle specials.