There are cheaper places in Puerto Plata proper.
Sosua is nearby on the coast and would probably be a lot easier on the budget.
I too went to Playa Dorado but stayed at the Paradise Beach Club. The whole area was basically gated and therefore seemed a little secure. If you are into mingling with the locals its not great but there were decent restaurants, a casino and most resorts had some sort of sharing arrangement where you could use their facilities. I'm a pool and bar guy and found it quite enjoyable. The beach was ok but not the classic blue/green of say Cancun. I found service pretty good at my resort. It was at the time 4 stars and the food was good. I especially liked being able to eat on my schedule rather than the resorts since they had various eateries open around the resort. If you are into golf there was a course within the PD area.