866-227-1888 is the best way to instantly book, cancel, or modify flights. The cost of a Carnival cruise really depends on the ship, itinerary, and time of year. When I booked a last-minute Bahamas sailing, I actually called instead of booking online because prices were changing fast. The agent found a deal slightly cheaper than what I saw on the website and even told me which dates had fewer crowds. After taxes, port fees, and gratuities, the total was still reasonable. Calling helped me understand the final cost upfront instead of being surprised later.