Saw this in the current Austpost catalogue at the Qld Garden City post office. Assume is nationwide? This is half the normal price (the normal $50 price isn't really attractive), and with the bonus 1GB data could be useful to someone going to visit Europe.
I didn't pick up a copy of the catalogue so can't check the full T&C which should be on page 3. The page on auspost.com.au only has the price but no mention of the bonus 1GB. Hopefully someone has the catalogue and can confirm how long the 1GB will be valid for.
I used these last year when I traveled to Europe, also when they were half price in an Aus Post catalogue. They're not the cheapest way of getting overseas mobile access, the most attractive part of them I found was free SMS text messaging between SIMs (I bought three of them). Note, though, that you must have more than $10 credit on each one for the free SMS. For me, they came pre-loaded with $5 credit so I still needed to top them up to access free messaging, with the minimum top-up amount being $25. I did find the online management of them pretty easy and topping up with an AU credit card was simple. Bottom line: shop around before you buy one of these. There are cheaper options (e.g. buy a prepaid SIM in the country you're visiting) but this one may have one or two options you find useful.