I don't know because I have gone by horseback. One time I did do Salto de Jimenao by car and it was a very small chump change fee to get in.
Here is a seven year old thread. It will always remain as one of my most enjoyable days spent in la rep dom.
http://dr1.com/forums/central/75400-photos-baiguate-waterfall-via-horseback.html
That is a different waterfall in the 'sticks' away from any roads and probably you need to go by horse.