Roberto,
Like I mentioned, we paid $189 for a week, which = $27/nt, water, sewer and electric included. Not sure if we were given a weekly rate, or if there even is a weekly rate at PDO, but they do know us there from our visits over 10 years of staying at PDO.
From my limited understanding, electricity is very expensive in Mexico, so most RV folks would probably NOT want metered sites.
I have no idea what rental rates would be reasonable for what you are offering, but I know I personally would not want to stay a block away from the beach.