Found 'em.
Market Video Games, C. por A.
Plaza Las Flores (Frente al Hogar de Anciano)
Puerto Plata, R.D.
809-586-4230 <office>
809-228-4961 <cell>
Randolph Rojas, Presidente (he speaks English well enough to get the deal done)
randolphrojas@hotmail.com
I went there yesterday with a buddy of mine who generated this request for information. Mr. Rojas had only a couple games in the store, but he owns a pay as you play video game shack around the corner for the kids as well.
We took a short walk over there and found a pretty extensive collection of copied (for 'chipped' x-boxes) and original x-box games for sale. 200 pesos for the copies.