Last year, I rented a 2 bedroom cabin with a pool for something like $1,200 pesos per day, but right now the name of the place escapes me. (I'll try to post the info later) It was 2 blocks from all the action, which in Jarabacoa is confined to a very small area around the local park.
If you're single and looking to meet people, the best places to do that are the local park at night, the various swimming spots, and a few places to drink and dance (try a place called Jalape?o); all near the aforementioned park. These places are usually a young (teens to 25) crowd.