Cruise.com via ShermansCruise offers a Princess Cruises 4-Night Cozumel Cruise for Two with prices starting from $558. (On the ShermansCruise landing page, scroll to the bottom and click "Book Now" next to the May 14 sailing date; we found lower rates during booking.) That's the lowest price we could find by $100. This roundtrip cruise aboard the Caribbean Princess departs from Fort Lauderdale, FL, on May 14. Book this travel deal by March 31.
With these companies, it might be easier than you think to negotiate your monthly bill down.