The Tanjung Belungkor ferry terminal has no exchange facilities, but the hotels will change money in a pinch, and most shops and restaurants will accept Singapore dollars at a 1:2 ratio. You can find an ATM at the Petronas gas station at the highway 90 turnoff to Desaru. However if you mainly stay in your hotel and only go for the hotel excursions, you can basically bill everything to your room and pay by credit card.
At the public beach, there are a couple of stores selling soft drinks, beer and the sort, but you can find a store that sells branded t-shirts, Malay batiks and souvenirs.
