This is pretty easy. I grew up in a school where everyone had Mercedes/BMWs/Huge Jeeps.
The way we got ours was the following (and this is the way most people did it).
1. Know someone "high up" in the government. Give them a small bribe, they make a call down to el puerto and you get to drive your car off into the wide expanse of Santo Domingo.......no tax no nothing. A good friend of mine was the grandson of one of the top customs officials, and I told him my parents wanted to bring in a new car..........so we bought it in Miami paid for boat passage......and no tax was needed. I literally just went down to the port with my friend and his grandpa and we drove it out onto the Malecon no questions asked.
My wife's brother used to bring in Porsche, Mitsubishis, BMWs and more using another connection he had. He would pay full price in Miami, say 50k for a BMW and sell it for 95k in the DR. All he was out was the 1k fee for the boat ride. He did this in HIGH SCHOOL (haha) with about 10 or 11 cars and made a cool 350k or so. The trick was to sell to the insanely wealthy people who didn't feel like going through the Miami trip/bribes to get it done. A lot of people do this.
It also explains why many families who were loaded in a certain administration suddenly go broke in the next administration, their customs "connection" is fired. Whoever runs in the port in the DR in any administration gets EXTREMELY rich.
The question of how can they afford it is pretty easy, Sto Dgo has a TON of extremely wealthy people......like any 3rd world capital. The gap between the rich/poor is huge.........very small middle class.
If you can get a successful industry running down there you pay slave wages.......and export at US/EU prices. It's a serious cash cow, which many pepper with drug bribes from South America.