The biggest expense you can save money on when taking a vacation is airfare. One way to cut costs is to fly on a chartered airline. They usually have special fares that are much lower than regularly scheduled airline´s fares. On this trip I was able to purchase my flight to Cancun for $229 including taxes. The next lowest price I could find was $449. That is a significant difference.
To be able to take advantage of these special fares it helps to be flexible on your travel dates and not need to plan too far ahead. I booked my flight two weeks before leaving. The company I used is Worry Free Vacations. They serve seven cities primarily in the Midwest. There are other charter companies that serve other regions. A look through your Sunday Travel section will probably enable you to find what companies are in your region.