With import duties, it's always going to depend on the specific country involved. I'd check with the customs office and find out about ways to get import costs down via quantity ordering, whether there is some special licence for importers and other commercial shippers, etc. Most island nations are almost entirely dependent upon imports to support their way of life, so many actually have numerous incentives available in the way of tax breaks. Come to think of it, if you research the matter you may find your niche right there in the form of some sector of goods that seems to get preferential treatment from a tax standpoint -- this would indicate that it's a good that is in high demand and short supply, to the extent that the government is taking steps to encourage people to import it and shippers abroad to send it.
Frank