It was a good experience... However there are many tour operators, eho charge something from 80 to 130 RM per person for the trip. If you are more than 4 person I would suggest you go upto the jetty and charter a speedboat, they charge something like 450 Rm for 3 hours journey. It is actually a winding river trip which ends with a swim in the sea. There are floating restaurants where you get good seafood from the days catch.
One thing though it is a Mangrove, one cannot expect the same flora and fauna as found in the sundarbans. It is more of a Commercial establishment than nature, As you will not find any other animals apart from..... Monkeys and a few eagles (they come for the food thrown from the boat) There is a crocodile cave but no crocodiles. However the journey itself is very good. However carry your own snacks and water as there is none inside the boats