I think if you do a search you can find more specific answers in terms of cost. I always end up landing in La Romana and then have to make my way to either Boca Chica or Santo Domingo. The cheapest way is probably by bus or gua gua but most convenient if you have luggage is the taxi. I ususally split the cost with a friend and in total I think it was about $80 CAN. When I was there last I had to travel a bit more west of Santo Domingo to el doce and that hurt...it was like $130?, I will definitely try to find another way next time.