I know that this is a different (but cheaper) solution but..
If you have a Digicel Phone chip in Jamaica, you can put 700 International Minutes of time (expires in 30 days) on your phone/chip for $1250 Jamaican Dollars. That way, someone can just call you from Jamaica for less than 2 cents US per minute.
I am not a talker so I find that I have to chatty mout a whole lot to use up the time!
I don't buy it every month but every couple of months. For me and my situation, it is a perfect solution.
Peace and Guidance