If you shop around, a cruise doesn't have to be expensive. My husband and I and another couple were on a 7 day cruise in January out of San Juan, PR. The total cost was $499 a person, not including air. We used frequent flyer miles so the entire trip was only $1000 for 2 people. That is VERY cheap considering that covers room, food, and entertainment.

We were on the ship "Adventure of the Seas". It is a very large ship (too big to go through the Panama Canal) but it could easily hold 1000 people at one time in the dining room.