Trade in to help with the purchase of a new iPhone. I'm on that new iPhone every year plan with Verizon. I'm really thinking about paying this iPhone (Jet Black 7 Plus) off and just keeping it as a backup this year.
I usually sell to our iPhones to finance the new, but I kept my 5S and my wife's 6 and use them as an iPod and/or to stream music and to entertain my kids when necessary.