Can't help you on the privatization date. I hope not, I want to play there in early March. Also, I still find it difficult to imagine they'd go totally private! If so, I can't imagine the monthly fees to be allocated to homeowners and members.
As for the transportation, I've never taken a taxi out there.
But, if you consider the airport to Cabarete is $25 for a 25 minute ride, your 1.5 hour ride each way + waiting on you 4 hours while you play for $170 is not totally out of the realm of possibility. You could get cheaper transportation using local taxis, but whether the vehicle is big enough to carry clubs & actually make it that far and back??
Consider renting a car. You can't really make a wrong turn, just head east out of Sosua and it'll be about 1 1/2 hours on your left. Total cost, probably $50-65 for a small SUV & you can use it to explore a little.