These articles take the wrong perspective - it's not that Australia is much more expensive in tech matters, it's that the US is much more cheap. I don't know where the recent Australia-specific articles are coming from, but it's been like this since as long as I can remember - that the US is much more cheap than any other country I'm familiar with for tech stuff, including Australia, but also almost every other count…
Part of this is that the AUD has appreciated in value so much over the last few years, and retailers are just not willing to drop their prices in line with the new purchasing power of the dollar. They also haven't caught up with the modern world in a lot of ways, considering that they still have a captive audience that can't just order off the 'net.
Part of this is down to protectivist legislation, for instance the price of books over there is huge and that is in part due to measures put in place to protect local authors and publishers. The net result though is that bookshops go out of business because people just get stuff online, delivered from other parts of the world. There are also weird legally-backed 'exclusive importer' agreements that result in the same phenomenon with other goods.
Part of the problem is retail rental rates are so high that traditional retailers have to have high prices, and in Oz the online services are usually run by the same folks. So again, business goes abroad.
Part of the problem is that some foreign businesses (Blizzard, I'm looking at you) just gouge Australians. Starcraft II was a hundred bucks to buy online from Australia!
So there's a whole culture of stuff just being expensive over there. The government needs to clean up their own act, but looking at what the private sector tries to pull is also interesting.
Incidentally Apple seemed to me to be one of the few organisations that were not overpriced over there, comparing US and AU prices on their store it was always pretty even (when tax was accounted for)