I had previously been to Cozumel and done excursions but our travel mates weren't very excited about the options they saw so I did some research and we decided to try out Paradise Beach. It was $2 per person for entry and that gave you access to chairs and the pool, but if you wanted to play on the equipment in the water it was an additional $10 per person. They do expect you to drink and eat while there. The pool was beautiful and relaxing, the beach wasn't the prettiest, but the water trampoline, slides, and other toys were REALLY fun! If my husband and I went back just us, we would probably just opt for the $2 per person and call it good. There is free wifi there, so it was nice to check in with family and friends and post some pictures! (It was pretty cold back home while we were away).
We took a taxi to and from, I dont remember the exact cost, but it was fairly cheap.
We did a little shopping in cozumel, but I didn't buy anything. It was VERY touristy.