i went to Nachi in January with a group. It's a beautiful beach. They were constantly asking if you wanted a drink refill. You could get beer, wine and frozen drinks. The bathrooms/changing rooms were very clean. It says a 3 course lunch, but you could eat anything you wanted, no one really kept track. You could eat right on the beach, or sit in the shaded pavilion at a table.
There isn't a lot to see if you're a snorkeler, but it was a nice beach day. And because of the cost there weren't many kids and the ones who were there seemed to prefer the pool.
I thought it was well worth it. It looks a little run down when you come to the front gate, but don't worry, it's really clean. No vendors trying to braid your hair.
I think it was about a 20 dollar taxi ride each way.