Also, T-mobile To Go, is probably the cheapest option after the 1st year.
Just like ATT, it's $100 for 364 days (at 0.10/min) it will give you 1000min for the year. After that if you add a $10 card, it will extend for another year every 364 days.
So Year 1 would be $8.33/month. Every year after that could be as low as $0.83/month, as long as you don't run out of min.
You would have to find out about coverage in the areas you visit though.
TM, Telcel, ATT
* 2015: Note 3, ZE600, 2720
* 2014: Galaxy Avant, Z600
* 2012: GS3, 2720
* 2010: BB8350i, 2720
* 2009: i9, BB7520
* 2008: Tilt, i450
* 2007: W810i, A707, 8125, BlackJack
* 2006: L6, Z520, 6682
* 2005: 7135, i600, V551, 6230, 6620, Z600
* 2004: V300, T610, 6035, 3390
* 2003: T720C
* 2002: Advx CDM4000, 9000, 9155GPX, Thera