Obviously you don't know Dominican Republic. Is the second biggest caribbean Island and sure there are places you don't like. I think the same thing must happen to your country, and all the countries.
Sosua is a beach for dominicans, there are few tourists. You should take a look at all the developments that are being build in Punta Cana, Samana, Juan Dolio, to see that the investment posibilities that offer the island are incredible.
I would never recomend a real state investment into a small island like the ones you are proposing because of the difficulty you have to arrive there, so potential buyers are much less.