This is great, thanks for the link! If cut-rate cost of living is what you want then come to my hometown in Indiana. Of course, there's no beach or scenery or culture, but it's cheap!
I've never lived in either Costa Rica or Mexico but I would urge you not to get too excited by the hype on Mexico's crime rate. The homicide rate is, I believe, at 17 per 100K while Costa Rica is a little over 10 per 100K. Keep in mind Mexico is an enormous country in comparison with Costa Rica and there are that many more sensational headlines simply because there are that many more people. And while Mexico is cheaper, I don't know that you get value for that price (like my Indiana example above).