Delta Airlines have round trip airfares travelling from Philadelphia (PHL) to Cancun Mexico (CUN) for $290, making 1 quick stop. This is a basic economy fare and google flight is saying 42% fare increase likely in 13 hours. I'd say don't wait, book it. Delta's basic economy fare allows a carry-on bag in addition to a small personal item. If you want, there's an option to upgrade to main cabin for $50. Still a great price!
Departs PHL: March 5, 11-13, 15, 18-19; April 3-4, 8-11, 15-18, 22-26, 29-30; May 1-2, 5-9, 13, 15-16, 22
Returns: Tuesday thru Saturdays.
My sample shows an 8 day trip because it doesn't come back on a Monday.
Use dates and book it on your favorite reputable OTA such as Orbitz [orbitz.com]
, Hotwire [hotwire.com]
, Expedia [expedia.com]
or Priceline [priceline.com]
. Bundling hotel with airfare will save money.