CheapCruises offers a Carnival Cruise 4-Night Western Caribbean Cruise for Two with prices starting at $348. (Scroll down to find this date.) That's $20 under last week's mention and the lowest price we could find for this cruise by $80. This roundtrip cruise aboard the Carnival Sensation departs from Miami, FL, on December 1 with stops in Key West, FL, and Cozumel, Mexico. This travel deal ends November 1.