comparative costs - Brazil/Cuba/Dom R/Mexico ?

I'm planning a 2 or 3 week holiday in January to one of these countries. In Brazil it would be Natal or possibly Salvador. Was wondering about relative costs for a couple staying in a variety of decent cheapish or nice mid-range places. Some travel and some beach time. I've been in all these countries before except for the Dom Rep, but some quite a few years ago.

Any info on prices gratefully received.