For anyone to be of help, you have to define what "moderately priced" means to you.

Also, are you just concerned with room costs or does the cost of airfares enter into tour budget equation? If so, where will you and your guests be flying from?

FYI - much of the Bahamas could be cool or even cold during the winter so those islands may not be the best choice if the you and your guests are looking to do beach related activities.

For what it is worth, start by looking at resorts in the Dominican Republic, Cancun, Playa del Carmen and Jamaica as those destinations are amount the most budget friendly in the Caribbean and will give you the best opportunity to find places that might meet your definition of "moderately priced". Avoid islands like Anguilla, St, Barth's, the Turks & Caicos, Grand Cayman and St. John as they are among the most expensive destinations in the Caribbean.