My daughter and her husband did find a beautiful two-bedroom apartment in Jaraboa for $6,500 pesos (including electricity and water!) It has a big, beautiful balcony and a huge, lush backyard. There was no "lawyer's fee" and it is a month-to-month lease. They are very happy!
If anybody in the future is looking, a DR1 member sent me the link to a nice guesthouse that also rents furnished long-term apartments (six months lease) at reasonable prices ($220 per month for a furnished studio.) If my daughter and her husband hadn't found the other apartment, they might have gone there temporarily:
Guest-House Jarabacoa - Dominikanische Republik - Domrep