If he can make a go of it as a foreigner tattoo artist I'll spank myself with Dominican salami. It is a stupid place to get tats, the colour fades loads as it is constantly moist with the heat and obviously the sun is a factor. If you notice Doms dark skin tats are always difficult to make out? well, it's not because of the dark skin, it is because the heeling process is almost impossible in the humid climate, it ruins the tattoo.
There are about 4 shops now on El Conde, none of which I would trust as they have no knowledge of cross contamination. The factor isn't the sterile studio, the factor is they have no education. They put on the latex gloves, then scratch their balls or pick up a coffee cup, that is obviously not sterile, Ive seen these guys at work and they are very obviously clueless. On the pluss side they all speak English, or at least a form of street scum spanglish they picked up before being deported.
I'm tattooed and yes I got one done in DR years ago, but I also had to have treatment for Hep C for 12 months self injecting which was a pain in the arse. So be aware, not everyone can recover from Hep C as I did, some people are stuck with it for life, and if that is the case then you can kiss your residency goodbye.