The Hotel Guaracuya in Barahona is near the port, on the main road, Av Enriquillo, traveling to the SW, roughly halfway to Pedernales from Santo Domingo, It is an inexpensive place to stay, nothing fancy. It is quiet. It was at one time Generalisimo Trujillo's many rest stops. It is owned by the government. It is modest to say the least but does have clean rooms with AC. Make sure AC is working. Its restaurant may be open or not. There are two decent restaurants across the avenida from the hotel. In recent months there have been talk of using part of it as a school for the hospitality industry. It has been a while since this poster has passed by there, things may have changed but worth a try.
Regards,
PJT