We have found the best deal to be United from IAD - direct flight to STT (3 1/2 hours ) Was $425.00 per person in January
The biggest surprise I found this year was the increase of Ferry cost - One-way was $50.00 per person and a $10.00 bag charge - I had budgeted $40.00 and $5.00
So total cost person from IAD to Roadtown was $545.00 plus checked bags