I want a 64gb iPhone 5, but I am not going to pay $849 for it (like it says for my upgrade status). I currently have a 64gb 4S with the grandfathered unlimited data plan. I was thinking, if I added a line to my AT&T family plan (which would cost me $9.99 plus taxes per month), got the iPhone 5 for $399, and then moved the iPhone 5 to my line, could I just get a cheap $20 go phone to plop onto the line I just added? No need for data on that and it would just be an extra phone that maybe my kids could use once in a while if they are out. With tax, that line would cost me about $13 a month so of course over 2 years it's about $312, but compared to paying the premium to order early on my line, at least it gives a useable phone if needed and staggers upgradeable lines each year. I've never bought a go phone...any issue moving one of those devices to a family talk plan? Thanks!