John is, as always, right on. Doing multiple transactions at the same ATM one right after the other can be scary, especially since most ATMs in EZE are still the older machine version where the ATM actually swallows your card... if the machine or the protocol that the issuing bank thinks there may be a security issue, it may choose to swallow your card. With all the hassles this involves, I think its best to come down with some USD or Euro cash.