It is soooooooo worth the price.

We did a B2B cruise last October and my wife was able to get one and we will do it again on our next cruise. We are a family of six and had Cabana #7 arrived first thing in the morning and was greeted by the CM there. He took us to our Cabana and it was beautiful. We had a small fridge filled with fruit, cold drinks and cold towels. There are buckets of toys for the kids and sunscreen for you to use all day long. We did nothing but sit in the water while all our kids played too. Lunch was a small walk down to Cookies and back to the Cabana with our lunch. They even take your plates away for you. My wife and I had a couple of drinks after lunch just sitting in the Cabana just relaxing as our kids played and floated in the water.
It was just so perfect, the weather, the water and you just couldn't have asked for a better day. You do have free rentals of bikes and I believe snorkeling equipment but we were having so much fun at the beach we never left the Cabana. At the end of the day they'll take you back to the tram stop so you don't even need to worry about the walk back.
Now that I've wrote all this I need to go back... Have a great cruise and enjoy the Cabana...