Not sure of the cost TOTAL would be for all 10 of you to take a taxi. I'll let you do the math.. We went to St. John on our own with 6 of us PLUS an infant. We rented a car ( they have vans, or A van available if you reserve in advance) for about $40 for the DAY, took a car ferry $27 ROUND trip from Red Hook to St. John. Went to Trunk Bay on our own. For that matter, you can go anywhere on your own when you want to with a rental car. I suppose with so many people, you'd need 2 cars, so do the math for that and compare how it'd work out best for you- taxis (which can add up X 10) or 2 cars and 2 ferry tickets. We personally found it EASY to find our way around with a local map, and NOT SCARY to drive windy roads and on the left. Unless you are one of those people who are scared at minor changes compared to what you are normally accustom to.. And if you ARE, take the cab. I hear form too many people who are just totally FREAKED out at the way the roads wind and how you are on the left. It didn't bother us AT ALL... At least we were in control of our own car, not leaving it up to God knows who is at the wheel in a cab. Ya know? We had time for Megans Bay in St. Thomas, AND Trunk Bay, but if I had it to do over, SKIP Megans and go straight to Trunk. Alot of people swear by Cinnamon Bay, never been there, but if it's nice as Trunk Bay I'd be great. As for you not missing the boat, can't help you there. Just figure out how much time you need to give all of you to get back. Car ferries run every 30 minutes, so we had no trouble. Get off early and you'll have to figure for yourselves when to leave where you are. You'll have more fun on your own, and GOOD LUCK..!