I trust the appraisals in the Caribbean jewelry stores about as much as I trust the guys selling goods from the back of a truck.
We have bought a few things in the Caribbean only because we "liked" them. I did get a good deal on a Breitling watch in Jamaica. I had to have it appraised for insurance purposes and the appraisal, at a local watch dealer, was $500 more than the purchase price.
If you like it, buy it. If you want it insured then have it appraised, at home, by a reputable jeweler.