World cruises are the crown jewels of passenger sea voyages and are priced accordingly. Considering what travel by air and land would cost for a similar journey, a cruise can still be an economical way to see the world. Even these high-end cruises can be a relative bargain when you consider that accommodations and meals are included. Silversea and Regent Seven Seas cruises offer the most all-inclusive fares, with no additional charge for nearly all beverages and specialty dining on board. By booking a world cruise early you might also receive a bonus, such as free airfare to and from the point of embarkation and debarkation. Other perks for world cruisers can include onboard spending credits, exclusive shoreside events, complimentary shore excursions in certain ports of call, and commemorative gifts.