Ending today, Southwest Airlines offers select 1-way fares to Mexico and the Caribbean with prices starting at $98.60. (Click on "Southwest Airlines" in the top line to see this sale.) That's the lowest rate we could find for select fights by $3. This price is valid on flights departing from Baltimore, MD, (BWI) with arrival in Nassau, Bahamas, (NAS) on October 21. Book this travel deal by October 2 for travel October 7 through December 16. Click here to see more routes.