In April we paid $10 per person (including luggage) from the St. Thomas airport to CA ferry. Here is the cost of taxis on Tortola. Looks like Road Town to Fat Hog's Bay (were DYC is located) will be $8.00 per person.
DYC has always sent a van from Sebastian's Transport for us. Cost was around $9.00 or $10.00. But that was last year, so check with the base. The crew list form has a space for arrival information.