Punta Cana
This Dominican Republic city has some modestly priced hotels that include free breakfast. It’s also known for its amazingly cheap all-inclusive resorts. You can likely find good airfare + hotel combo packages as well.
St. Lucia
You won’t have to spend much money to enjoy a stay on this island. Not only are hotels and meals inexpensive, it offers no shortage of fun things to do for free, like visiting the Castries Market, going on mountain trails, sightseeing along volcanic beaches, and so forth. The only downside is its remoteness from the US, so you might have to wait awhile for a connecting flight.
Montego Bay
Jamaica is worth visiting at least once in a lifetime, and Montego Bay is a must if you are on a budget. There are plenty of all-inclusive resorts with affordable rates. This is a very well-developed area for tourism – especially around the north shore.