Hi... Cenotes ( which you can enter y car ) requires a fee. Those are owned by the ejido or private. They make a big business out of it no question about that. I actually got trained by Steve Gerrard a long time ago as a full cave instructor and been diving most of those caves and cenotes for the past 10 years. They're amazing no doubt and most of the entrance to the cave ( Cenotes ) are very hard to reach because they are far away from the main road. The owners make it possible for us to reach them easily, like Dos Ojos, Taj Mahal, Mayen Blue, just to mentioned some . Though , between 5 and 10 usd a person, I think its fair to pay the entrance and have a nice clean beautiful place to enjoy.
Back to Cancun....the Beach Palace, not much Beach over there, that right. But you can take a Taxi ( if your photographer don't have car ). South by Westin Regina.... beautiful Beach or behind Hard Rock Cafe. There're are a lot of options if you know your way around.
Well Iam not a Lady but always like to help.....