Unfortunately you can not always get 30,000 JMD, as times it is limited. My last trip in Dec it was hit or miss, with several trips the ATM only dispensed 500JMD bills. So I had to do two transactions to get the money needed and paid the extra fees. could barely close my freaking wallet. I even tried multiple machines as well.
Take some Canadian for standby as the last thing you want to do is skimp by if the ATM's are not playing nice.