I've been going to Friar's Bay (Anse des Pères) for years - loungers/umbrellas are free if you are eating/ drinking there but cushions on the loungers cost $3, if you choose them.
Now, 2 loungers, an umbrella and cushions are discounted to those who are eating there - to $10. Still a great deal (and I'm about to eat lunch, assuming the food is still as great as ever) but I thought it was worth mentioning. And remember that credit cards are not accepted.