I have Verizon cheapest smallest phone...only want it for emergency use. Pay in advance, add $$ as needed OR by the expiration date. I always pay $30 and that buys 3 months before next expiration date. I figure $10 a month a bargain, for the emergency use.
My balance hovers around $200 because I seldom use it. I get texts which I think costs 10¢, but not sure. This works fine for me, an older senior citizen, who still drives.