Why do you want to buy it in SXM? If the reason is to save money, my understanding is that the prices are not that much different than in the U.S. If you buy it in the U.S. presumably where you buy it will size it for free and ultimately if there are any issues, it would be easier to have it handled in the states, although several of the SXM jewelers have US service centers. So if the only reason to buy in SXM is to save money, I wouldn't bother. However, if you both have a big connection to SXM and it will be a sweet memory for you for years to come, that you bought it in SXM, then by all means, buy in SXM. You'll have to pay for the sizing in the US, but you should have no problem getting it done. I somehow managed to lose the diamond out of my engagement ring a few years ago, so we replaced it in SXM. I have a lot of jewelry, including costume jewelry, that I love even more because they were bought in SXM or on a cruise.