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I'll be traveling to the US (specifically Fairfield, Connecticut) in about 2 weeks. Which provider has the cheapest prepaid data rate? would I be charged roaming if I went to a different city or state? (e.g. New York City). As much as I'd like speed I'd be more concerned about coverage. How soon would they kill the number once I come back to my country? Would I be able to use the same SIM card if I went to Miami in 6 months? If so, being that far from where I bought the SIM, would I then be hit with roaming charges?