But my clear advice to you is to either accept the absurd $300 dinner or rebook somewhere else.
I would agree in principle, but
thehaloboy has booked an advance purchase rate, so he cannot cancel. But perhaps they agree to cancel it without charge based on the NYE buffet information not available at the time of booking. Or perhaps they agree to not require booking the buffet.
In any case, I would deal with this issue before going there. French Polynesia is just too beautiful to spoil your short time there by dealing with such matters!
In any case, 300 USD p.p. is just ridiculous. I hate those buffets and avoid them. Bora Bora has a number of perfectly acceptable to very good restaurants and I would much prefer to spend the evening there than in one of the hotel restaurants.