The cost of a seven-day cruise can vary greatly depending on various factors such as the cruise line, destination, cabin type, time of year, and additional amenities. On average, however, a seven-day cruise can range from around $500 to several thousand dollars per person. This price typically includes accommodation, meals, entertainment, and access to onboard facilities and activities. Luxury cruise lines or specific itineraries with premium features may be at the higher end of the price spectrum. It's important to note that the cost does not usually cover optional expenses like alcoholic beverages, spa treatments, shore excursions, gratuities, or travel to and from the port of embarkation.