what? 4 million pesos does not go a long way in SD. i have seen apartments at 10 or 15 million pesos. now, that is crazy expensive. but 4 million pesos does not sound insane. there are more expensive apartments in santiago or cabarete/sosua.
bear in mind few things: SD is a capital. every capital in the world has elevated prices, especially in prime locations in the city center where space is so limited.
then: mortgages are not popular in DR. people but for cash of finance within family. rates are sky high.
finally: for many dominicans appearance is everything. hence expensive cars and living on rice and beans, because it is more important to show off. people with money will pay the price for a good address.
now, personally, i am all for buying. i am silly like that. i feel safer that way, maybe, and maybe this is the part of my culture. so buy if your mind is set but buy wisely. there are, occasionally, good deals to be made. sometimes people leave due to personal reasons and they want to sell ASAP, even at less. sometimes people die and their kids need cold hard cash, now.