Just google st Barth commuter. That's the name of the airline. I just booked online. Not sure if there is a savings if you do it at the airport. But because we wanted the earliest and latest flights we booked in advance. Took taxi to town and shopped a bit. Then took Taxi to St Jean Beach. Hung out at the Tom Beach Hotel. Have done Nikki Beach and just "too much" for us, wanted to try Eden Rock but wallet said Tom Beach! Nice day and then we just walked up to the airport!!