It's not much better with overseas ATM fees. Whilst in Vietnam recently I had 2 methods of acquiring Dong. The first was to change cash at hotel desks, travel agencies, jewellry shops, etc. Never any problem and always a good rate (above 20,000 Dong to the AUD).
The other method was via ATMs on the Cirrus network. This was about 50/50 for working as sometimes they seemed to have run out of money or couldn't complete the transaction or were just having a bad day. But when I succeeded I almost wished I hadn't. For a typical 2,000,000 Dong withdrawal I was charged about $1.50 by the ATM owner (disclosed up front) but then had to fork out $5 and 3% to the CommBank for the privilege of sending some bytes across to Oz. So the effective "fee" for using ATMs was about 10%. Where's the ACCC when you need them?
And when you compare the effort involved with money-changers having to keep tabs on fluctuating exchange rates and going to the bank to "sell" all the various currencies they collected and then transport and secure large amounts of local currency ..... it beggars belief that they can do so for even the same cost as an ATM - let alone 10% cheaper.
I've just returned from SGN.
I was trying out my brand new (HK) Standard Chartered Priority Banking ATM card, which is a PLUS card that promised no fees overseas (like fruit juice, I think they meant no *added* fees - they'll still pass the 1% from Visa/PLUS on).
I was charged HK$2,046.03 (around A$262) for VND5,020,000, which is VND2,453.53/$, which is 1.5% of the Oanda rate (2,489.68) for that day. It isn't the Oanda rate +1% (2,464.78) but it's not Oanda rate +1% + HK$25 full PLUS charge either.
Same as you I got nickeled and dimed by the ATM which asked for VND20,000 (around A$1). I wonder is that common in Vietnam? I wanted to cash out in the airport so I can start tipping the driver and the doormen at the hotel (and rather not do US$1s).
Post-ante I thought I would've been better off changing at the currency exchange but in previous travel ATM beats changing cash.
I empathise with Australian ATM cards problems withdrawing overseas tho. Last time my mates went over with me to Shenzhen, they can't withdraw more than approx A$200 per person in Renminbi from Chinese or foreign banks' ATMs, and I know they were going to be bilked around A$5 or so for the privilege. I ended up floating everyone enough Renminbi to have a good buck's night up north, and asking them to reimburse me in AUD so I've some cash to spend on my trips back.