There is an Express Bus to Santo Domingo from the Bavaro bus stop that leaves at 4 pm. If your flight gets in at 2 pm, you could make this bus, would be kind of risky if your flight gets in at 3 pm. These buses leave on time. The next bus is at 7 in the morning. It takes almost four hours to get to Santo Domingo. The cost is less than US$10 (about RD$120, price could have changed recently.) If you miss that bus, catch a bus to Higuey (about RD$25). These buses leave about every 15 minutes. From Higuey, buses leave on the hour for Santo Domingo, with the last bus at 6:30 pm, so you have time to make this bus. The cost to Santo Domingo from Higuey is less than RD$100. Just check what the going fare is. It is a standard fare. You should cash money into pesos to pay for the fare. The bus will probably drop you off in Enriquillo Park -- in the midst of the Avenida Duarte bargain price shopping district. From there you can take a RD$60 taxi to your destination in Santo Domingo, or just catch any of the cheaper transportation ways any fellow passenger will recommend.