Really leaning towards Panama on RCI
Only $250 per person (interior) for 7 night southern Caribbean cruise out of Panama, Dec 7th-Dec14th. Chicago to Panama RT is $388. I might just buy two tickets and do a no show.
Not exactly what you are looking for but its close, let me know if you are interested.
Royal Caribbean, Independence of the Seas, Dec 21-29, Fort Lauderdale, I'm going with a family of 7 so I have a room to myself. Actual cost including taxes and gratuity is $985, I would do it for $450. I'm a male, 35, educated, respectful and most likely be out late every night.