If you are with Dominicans let them buy the tickets as gringo prices can apply.
No, please don't. If you are a tourist please pay the tourist price. The difference is only 100 pesos and this enables local schoolchildren to enjoy the facility. Thank you.
Lambada is right (as usual)! Sorry, I expressed myself badly. I am sure no visitor would begrudge paying 200 pesos which is a reasonable charge. I meant to write that if you are taking and paying for a group of locals (as I did on my first visit), be careful not to pay tourist prices for each of them as I nearly did.