These buses are privately owned and don't have the infrstructure of a Caribe Tours or a Metro. No reservations are required.
I know there are several buses and maybe even a big van or two that leave at different times. Hopefully others will be able to help with information on their schedules and departure times.
The only one I know any details about is Transporte Pepe. It runs one bus and has been in business for a long time. It departs from Santiago, as far as I know, at 1:15 pm The last information I am sure of was given me in 2003, so may be different now. But at that time they were departing from the Aries Taxi office at the corner of Pero Francisco Bono and Lili, Tel 809-582-2134/5709. If that is no longer the departure point, they should be able to tell you where it is now.
The owners/drivers live in Samana. The number I have for them is 809-248-5328 and cell 809-953-6447.
Hopefully others can give more information. But I am certain there are privately owned buses that are going back and forth between Santiago and Samana, passing through Sanchez before the get to Samana, where you can get transport to Las Terrenas.
Regarding cost, don't know what it is these days. Probably in neighborhood of US$6 or 7.
