I have a 16GB wifi iPad 3, I have decent wifi locally but want the option to have 4G for travel. I also have a Galaxy Nexus on Verizon. On a 4GB double data plan. I have a 4G iPad in the cart at Apple but this is a lot of $$$ that could be going toward upgrading my MacBook Air. Should I get a prepaid mifi device that I only pay for when needed? Should I just add mobile hotspot to my current phone plan or just bite the bullet & buy another iPad?