No, not always. If you plan on going shopping on your cruise, especially for pricey items such as jewelry or watches, you should first acquaint yourself with how much they go for at home or on discount websites. This way you'll be able to easily spot any real deals. You may also find price differentials between onboard shops and those on shore.

No. Before you go overboard with your shopping, make sure you understand the U.S. Customs and Border Protection rules regarding what you can bring back duty-free. There are limits to how much you can spend outside the U.S. without paying a tariff when you return home.

Yes. For instance, on Carnival we spotted a bottle of Grey Goose vodka for $30 (the U.S. retail price is $36.99). There are also duty-free exclusives that you won't find on land, though there are restrictions on how much you can buy (see the Customs rules). Also, if you are flying, you'll need to pack the bottles in your checked luggage. Be careful about how much weight you add to your suitcase; all your savings will evaporate if you get socked with overweight luggage fees at the airport.

You will always save on sales tax as compared to buying at home, as well as the duty, but there may or may not be other discounts. That designer handbag, for instance, may be the same price as at home, just minus the taxes. Among other popular items, expect to save about 25 percent on perfume and about 10 percent on makeup or designer sunglasses. And for fine jewelry, you may find savings up to 40 percent.

Yes. During your cruise you will see all sorts of promotions at the ship's shops, including two-for-one pricing on T-shirts and cut-rate prices on costume jewelry. It also sometimes pays to wait until later in your cruise to see what sorts of deals emerge.

In some cases yes, especially if you're eyeing a top-end item such as a designer watch or diamond ring, and especially if you're at a duty-free shop on shore. If a jewelry company is on board your ship doing a trunk show, you can negotiate directly with the company's salesperson.

This will vary by line. Make sure you understand the cruise line's return policy and also any applicable warranty information.