On 50K US you could live comfortably. That is more than my income.

The trick if you don't have unlimited income is to live on the economy. By that I mean forget about the exchange rate. Tourists are always saying, "that's only $2 US", or something like that. Instead, think about whether you want to spend 35 pesos. I don't mean you have to squeeze every peso, but when spending RD$100, keep in mind you are spending 100.

If you do work here, or anywhere outside of US, for a national company (rather than a branch of a US company) you can earn up to approx US$70,000 tax free. You have to report income, but there are special tax forms for this.

I get social security and it is subject to tax. Annuity payments or similar from investments in US are reported by payer and subject to tax.

We live better here on our income than I could in the US. And certainly our condo is far beyond our price range there. One reason I stay here is that I couldn't afford to live there. (But that is only one of the reasons.)