RE: Can I live in Costa Rica on a $2,500 monthly budget?
Yes. If you can live in the US the way you would like on $2,500; you certainly can in CR. If you can do alright in the US on 4k you should do fine on $2,500/mo.
If you need to live on the beach, have 24 hr AC, a new car, and so on and so on, that might be tough. I know several people that live simply, but comfortably on $2,500 or even less. I rent a nice, small, clean and simple condo in a gated area for $500/mo. If housing is 25%-30% of your budget you can see this will work.