Panels in the DR are inexpensive. I did a quick search and found 410 watt panels for 8000 pesos, which would be about 34 cents per watt. They do not have a high tariff like in the US. There is no sense in arguing about the cost until everyone knows all the variables. Do it yourself vs having someone else install it for example. Also, do you plan to live there 12 months per year? If not, is there someone there to watch your system and make sure the cheap batteries have enough clean water put in them occasionally? If not, you may want to use a more expensive lithium battery that you can drain down below 50% and not worry about water levels. For example;
BYD, BYD-B-PLUS-H-2.56, BYD BATTERY 2.56KWH LITHIUM IRON
Is the racking good quality to prevent Hurricane George, or Ladrone Jorge from removing the panels? Is your local grid a steady and "clean" source of power? Some of the higher quality inverters will not function if the Hz and volts are not within a certain range. Some electrical grids cannot offer that in the DR, so you need to test your local source of power to make sure that your inverter will not shut off even when the power is on. SMA inverters shut down outside of 59.3 and 60.5 Hz. If your power is unstable or off for 14 hours per day, you may just want to go off grid.
You can buy cheaper inverters, but they will also cook your more sensitive appliances and electronics.
I think solar power is great. I have a system in the DR for 10 years, and it is working fine. Before you install it, you should put a lot of thought and research, to make sure it works well for you.