On Punta Cana, understand that the Dominican Republic gets over 2 1/2 million international tourists a year, 10 times as many as Belize.
The reason is simple: Low prices for package vacations, mostly from Europe.
Punta Cana has big, cheap, all-inclusive hotels. Several of the 80 or 90 hotels in Punta Cana have 700 or 800 rooms, and I'm sure that there are more hotel rooms in Punta Cana, DR, alone than in the entire country of Belize.
However, most people in Belize (and on this forum) say they don't want big low-priced resorts in Belize.
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On a separate point, air fares to Belize are high right now and are high much of the year. BUT, at times there are still deals. For example, my kids flew down to join me in Belize in June. My daughter paid US$325 roundtrip including all taxes and fees from Charlotte, and my son paid US$350 from Boston.
--Lan Sluder