Saw a similar deal in an email yesterday from Arthur Frommer's Budget Travel (don't need to be a member of anything to get the deal, either!):
Roundtrip airfare and seven nights at a new beach resort in Ambergris Caye, Belize, starting at $439 for Washington, DC departure. The package includes seven nights at the Banana Beach Resort in a veranda or balcony suite, each decorated with locally made Rattan furniture and art from the Yucatan and equipped with a full kitchen, a living room area and a private bathroom for each bedroom. The beachfront resort offers Jungle River cave tubing, diving, snorkeling, fishing and tours throughout Belize.
Valid: Sept. 1 - Oct. 31, 2005; add $75 for departures before Sept. 1 or after Oct. 31, 2005.
Add $150 for Miami, New York, Philadelphia; $170 Atlanta; $190 Boston, Dallas, Houston; $320 Los Angeles, San Francisco; $340 Chicago; $370 Denver, Seattle.
Here's the link to the referring website: http://www.budgettravelonline.com/bt-dyn/content/article/2005/08/11/AR2005081100778.html
And to the provider: http://www.jetawayholidays.com/