We stayed at Mt. Vernon using one of the sponsors of TTOL--studiosxm. It was a great property with a perfect view. We rented a car and drove to Club O several days. We walked to Club O one day just incorporating a daily beach walk. The drawback to walking is that the beach bag can get a heavy quickly if you are carry a water bottle or two.
We are beach bums as well so we drove the Mt.Vernon/Club O circuit--maximizing beach time, plus we were able to make stops at favorites like Yellow Sub or Rancho del Sol. We enjoyed late nights on the balcony stargazing.

It was relatively cheap. To us anyway.