 I got to the customs desk in the U.S. to declare my wines, and I was surprised that the value of the wine was of no interest. The number of bottles, 12, was, and I was charged 10 cents duty per bottle. Since then, I've brought cases home from Europe, often declared them, and customs didn't care and waved me through. Remember, if you buy a bottle at an airport duty-free store abroad, you can carry it on your flight. But if you've got to pass through security while changing planes when arriving in the U.S., you'll lose that bottle.