Congrats on your upcoming wedding!! I'm getting married there on May 9th, 2017.
I just looked quickly for you... If you decided to have your reception at the beach bar, a $300 fee applies if there's no food. And there's a $12 charge per person for the open bar, without food service.
You also do have to pay for any upgraded chairs if you chose to have any, as well as whether or not you wanted to upgrade to an actual dance floor (these are insanely expensive here, starting at $1000) I'm choosing to use the floor of the beach bar, and not have an actual "dance floor"... Any decor or linen upgrades would of course also be more.
Let me know if I can help with any other questions I've gotten quite a bit of information from my planner that I've been working with. Booked my wedding through Luxe Destination Weddings! They've been great.
Where are you flying out of?
I've been stalking instagram like crazy for pictures of setups at the beach bar. If anyone has any of these please pass them on!!