My FI and I are marrying in Punta Cana on Canada Day next year, and after enough thought we decided to do a Symbolic Ceremony in Punta Cana and are going to get married here in Canada on June 21st (the first official day of summer!) to avoid the extra cost and paperwork. We told my parents, simply because we need witnesses at the wedding at the Courthouse, but even my FI's parents will be in the dark about it! For us here in Nova Scotia it costs only about 480 dollars total for the licence, cert., ceremony and change of name, compared to about 1200 for a legal ceremony in DR. I mean to each his own, but this is what works for us!
Good luck deciding!