I have bought about 30 A/C splits so far, and I tend to buy them myself from somewhere like Megafrio (809-788-8665), they deliver free of charge. And then get someone else to install. At least get a price from Megafrio to compare with an installer. Installation should come in at about RD$ 2,000 upwards, depending on how complicated it is. Make sure you get an Inverter, this is very important, and make sure you get a good brand like Lennox or Westinghouse. A/C's should be serviced every few months, again this is very important, and you normally pay around RD$ 1,000 per unit to have them serviced. (All these prices are based on the Colonial Zone Santo Domingo).