I'm looking for some opinions from folks who have an understanding of how the T-Mobile Jump On Demand plan works (and please, no comments on why carrier X is better). First, I don't even really know what my options are and T-Mobile won't even tell me unless I go to one of their stores. I'd prefer to just have everything figured out before then so I can just be in and out. So I've got a 64GB 6S Plus on the Jump On Demand plan, and the condition is pretty much perfect. In mid-July I'll have to pay off my phone for $218. So here are the options as I see them: 1: Trade in for a 128GB 7 Plus, then trade in again in September/October for the 7S/8. This is the direction I'm leaning in, but does anyone know if I'll have to pay anything up front for doing this? 2: Pay off the 6S Plus now, then sell it when the new ones come out. I've started to hate doing this because CL and eBay are nothing more than cesspools of scammers. I've done it in the past, but it's something I really would prefer to not do anymore, even if it means getting less money for my phone. I'm open to other suggestions as well, but I'm really leaning towards option 1. If anyone can give me details on what to expect as far as what I might be expected to pay I would be appreciative.