I think the only thing on Rocky's menu exceeding 350RD is his large order of ribs, which is still a really good deal given the high quality and quantity of the food served. That, and you get to hang out with the legendary Marco, whose advice is easily worth several times what you paid for the meal.
Another favorite is Morua Moi, which has a nicely diversified menu of high quality items for around 350RD as well. They do have more expensive items such as lobster and other seafood dishes, but it's one of the better deals in the town. Alexandra is rapidly becoming one of my favorite proprietors in the DR.
There are many other fine spots to be sure, but I'm something of a creature of habit. I don't like having a queasy stomach, either because of something in the food or surprises on the bill. Both Marco and Alexandra are owners of establishments that consistently serve up quality food at reasonable prices in very comfortable surroundings.