I've considered Uruguay and Belize recently. I've backed off from Uruguay do to what seems to be the high cost of living. I need to work for another decade at least.
Uruguay does have a higher cost of living than most 3rd world countries.
How high that cost of living is depends on what level of lifestyle you expect. If you want to have all the luxuries of upper middle class first-world living, it's going to cost roughly the same.
If you're more modest or bohemian, the cost of living will be cheaper than in most 1st world cities.
Just for reference:
a 1-bedroom apartment in a good part of town, nice but super fancy, rents at about $420 USD, plus about another $50-150 in utilities.
Groceries and food are cheap (I can feed myself for a week very easily with good varied and healthy groceries for about $25; and an average main course at a typical restaurant might cost $10; a cappucino about $2.50 at a cafe, a beer maybe $4).
Imported stuff is very expensive, though getting cheaper than it used to be (I used to say anything technological costs twice what it would cost in north america, but now that's closer to only about 1.5x more).
Health care (you don't want to use public health care here) costs about $75 a month for basic coverage. But expect to pay a couple of hundred extra in "tests" and prescriptions any time you actually get sick or injured.
The really expensive things are owning a car (gas is expensive, and costly licenses and parking permits), raising kids (private schools are pricy, and even most of those aren't very good here).
And the real problem is that incomes here are low. So if you're planning to get a job here and live off that, if you try to teach english for example, you'll be working long hours and making about $700 a month if you're lucky. Owning your own business here is also likely to bankrupt you. So you need to either have a lot of money (and buy real estate, if you like), or be on a fixed income from foreign sources (retirement, pension etc), or work for yourself in a business that's done online and where all your business is out-of-country.