The high season in the United States for Caribbean travel is during the cold winter months from December to March. In the late spring, summer and fall, the resorts are in the off-season. In the late summer, the Caribbean islands experience hurricane season, which can give way to deeply discounted vacations and lower prices for flights. All-inclusive trips during the off-season are a fairly reliable way to save, especially in the summer if you don't mind the weather and you would like to have the resort all to yourself.
Believe it or not, there are some budget-friendly accommodations that offer all-inclusive packages. These resorts may not be five-star quality, but they can offer you comfortable lodging, activities, entertainment, meals and drinks for sometimes as little as $100 a day. See the Resources for lists of highly rated budget all-inclusive trips.
If you are more interested in exploring than eating or spending time on the beach rather than shopping -- or vice versa -- you can save money on your all-inclusive vacation. Look for packages that offer a select list of amenities rather than a giant list. If you do not plan to take advantage of a wide range of the possibilities in an all-inclusive package, try finding a package that is more suited to what you will actually use at a lower price.