When should I buy currency?

SHOULD I BUY CURRENCY FOR MY DESTINATION AT THE AIRPORT BEFORE I LEAVE, OR WHEN I REACH MY DESTINATION?

Based on my own recent experience on a trip to New Zealand, the answer is not until you reach your destination.

At Sydney Airport's international terminal, I approached a currency exchange counter and asked how much it would cost to buy 200 New Zealand dollars. The answer was $230.35.

After passing through immigration and security, I asked the same question at another exchange booth and was told the cost would be $226.

In Auckland Airport's international terminal, at one booth I was quoted a price of $200 to buy NZ$200, at another 50 metres away the price was $206.

Finally I withdrew NZ$200 from an ATM inside the terminal using a 28 Degrees MasterCard. The cost was $188.33, plus a $5.49 cash advance fee, for a total of $193.82.

Exchange booths require a wage-earning staffer and they must hold large amounts of various foreign banknotes, effectively a non-performing asset. Therefore they expect to charge a premium to any traveller who uses their service, and especially when they are providing an offshore currency.

An ATM on the other hand costs far less to operate and maintain and doesn't have to hold wads of foreign currency, and therefore it can offer a more attractive exchange rate.