As much as I love to cruise, some people love all-inclusive resorts. I have to admit the all you can drink factor is very appealing. I have not noticed any really cheap airfares to Cancun but Frontier has the flight from SLC for $326 per person. If you get 5 nights of an all inclusive hotel on Hotwire for $500 (3-1/2*) all you will really need is tranfers to the resort.
Dates December 5-10, more dates possible.