Ok from understanding, if I do next for 24 months with 6 plus 64gb it would cost me $35.42 x 24 = $850.08 which is how much the phone without contract right now, correct? Not including the $15 if my family switch to the new promotion.
I'm currently with contract so it will cost me $440 + ($40 x 24) = $1140 after 24 months.
So with next after 24 months, I own the phone, right? There's no more $35.42 installment and I can trade it for a new one or keep it? Sorry for asking so many questions.
I think you're math is correct. With the next 18, you would pay $15 a line and pay $35.42 a month for the phone. Yes after 24 months, it's all yours. It's basically interest free financing for the price of the phone. You can trade in the phone after 18 months and att will let you finance a new one or make 24 payments and you won't have to trade anything in as the phone is fully paid for. It's easier to sell it in a year and pay off the balance on it and this way you can upgrade anytime you want instead of waiting.