Vacations to Go offers a Carnival Cruise 4-Night Western Caribbean Cruise for two with prices starting at $388. That's $30 under our mention from April and the lowest price we could find for any such cruise in October by at least $90. This roundtrip cruise aboard the Carnival Fantasy departs from Miami, FL, on October 31 with stops in Key West, FL, and Cozumel, Mexico. Book this travel deal by November 1.