Do you want to go to Cancun? If not, why not look at flying into Merida? Unless you're interested in visiting Chichen Itza and Valladolid en route (from Cancun), you can save yourself a pretty monotonous and costly 3-4 hour ride. (And, you can also zip over to Chichen and Valladolid from Hacienda San Jose.)

I've booked into CUN when going to the Yucatan since it is usually ~$50-100 cheaper and have regretted the decision each time. (I'm a slow learner sometimes. ) Cancun car rental pain + additional car rental costs + gas + tolls + driving time may not be worth the up front ticket savings.