It cost more to fly from San Juan to Beef Island than to fly from Columbus,OH to San Juan. About $400. CMH to STT in Novemberis about $550 right now so the premium to EIS would be about $250/person against worst case $120 from STT to Tortola.
Add to that from many locations total travel time can often be less via STT.


Travel is fatal to prejudice, bigotry, and narrow-mindedness, and many of our people need it sorely on these accounts. - Mark Twain