AT&T, T-Mobile, and Verizon Wireless have each introduced new "early upgrade" programs that allow wireless customers to trade in their smartphones as often as every six months. Are these plans really worth the cost? And which one offers the most value?I try to answer these questions in this Ask Maggie.As T-Mobile CEO John Legere said when he introduced his company's new Jump program, "Two years is too long to be locked into a phone. You should decide when you upgrade, not your wireless company." Wireless consumers hungry for the latest and greatest phones share this sentiment. But even with the slick new plans, frequent upgrades will still cost wireless subscribers a pretty penny. In this edition of Ask Maggie, I break down the true costs of these plans and show how much you will really spend if you subscribe to each of these plans over a two-year period. I also explain which carrier offers the best value when it comes to a frequent upgrade plan. But I also show how costly it is … [Read more...] about Which device early upgrade option offers the best value?