I will be in the DR in January and February based on the North Coast. So you would just play for a short commuter flight from Puerto Plata to Punta Cana plus the hotel.
I agree with many of the other photographer's sentiments here. From what I've seen it looks like Photo Souvenir does some nice work. But it can definitely be worth it to hire your own photographer if you are looking to capture the experience of the entire day in addition to beautiful beach photographs.
For 8 hours I typically shoot 2,500 photos or more and turn over 800-1,000 on cd. I believe this is not uncommon for many of the north american based wedding photographers.
Here's a link for a recent non-destination wedding. Jeff and Josie
Again, it depends on the style your looking for, how you click with the photographer etc.