Yeah I can tell you from experience shipping to the Caribbean is HIGH.
Whatever you do, do NOT trust the USPS Global Priority rate when they say it will be 6-10 days to a Carib island. They no longer have any other service other than Global Priority, and it isn't 6-10 days... it took SIX WEEKS. And this is multiple shipments, not a one-time thing.
USPS SUCKS internationally these days. //content.invisioncic.com/y282845/emoticons/frown.gif.a3531fa0534503350665a1e957861287.gif I'd definitely go with FedEx in such cases.