Rocky's in Sosua is cheap at $15/night. It's not the Four Seasons, but it's not bad either. It's basic, but I'd stay there again. Rocky is a member of this board as well. Very cool dude, very cool staff.
In Cabarete, I have stayed at Hotel Casa Blanca for $25/nite. Check it out at
www.casablancacabarete.com. The guy who owns/runs it is Holger. Cool dude as well. I would call and make arrangements.
Hope that helps.