We're in the area often.
There are numerous places to make a jump-off point to Salto Limon.
The one we chose for many reasons...one being the "Dominican" feel and not being real touristy...is Nega Parador #5. The proprietor, Dona Nega, speaks only Spanish and her phone is 809-462-4727. She owns many horses and has a full staff to go to the falls. The food at her place is great!
Tell her the motorcycle touristas said "hola."
I can't believe a taxi from Santa Barbara de Samana to her place could be more than 300 pesos. I'll bet Dona Nega could arrange transportation.