Thanks to the tips from folks here over many years, I've become pretty good at searching fares and options. Lately, the cheapest fares have involved overnighting in San Juan and taking the early morning Seaborne flight. Even factoring in the hotel, we save $$$.

Being on an out island, it's much better to arrive before nightfall, which makes even the 6:10 pm arrival a close call. And that is often the most expensive flight.

If you have enough people, another good option is flying to St. Thomas and chartering a plane to Beef Island. We did that in March and it was wonderful.

Could American route you through Dallas, with an overnight there?