Hello, I currently have 3 lines on my Verizon account: 1 Smart phone line with unlimited data and 2 dumb phone lines. I use Galaxy Nexus and do need to upgrade it, however, I need to upgrade one of the dumb phones to a smart phone. Obviously I cannot get unlimited data anymore for any new dumb phone upgrades. What is the cheapest option for upgrading a dumb phone to a smart phone and in the process not loosing my unlimited data? Thanks.