The title of the parent post is totally misleading and shows a clear sign of not having passed basic algebra. Australians are going to pay 15% more for their apps and not 50%.
First $1 AU = 0.70 US. Taking currency conversion into consideration, this means that a 0.99 App in the US store would cost $1.29 AU.
Next, we see that that $1.29 apps are being raised to $1.49. That's a $0.20 AU or a 15% price hike.
Converting that back to US, we see that the equivalent cost is $1.09 US vs the original $0.99 US. This $0.10 US difference equates to an actual 10% markup between the AU and the US markets.
I would have to assume that Apple is passing on their operational overhead costs in the pricing of apps.
Something to think about - developers are permitted to set the price of their apps. In the US, other than free, the minimum cost is $0.99 as that is the lowest tier that Apple permits. Should developers be forced to take a pay cut because they are selling in a market with a poor currency exchange rate or should they be permitted to sell their wares at a specific price they deem appropriate?
Given that Apple is going to reintroduce a $0.99 tier in those markets, should developers be expected to sell their apps at a 30% discount in the US as well? After the Apple tax of 30% on goods sold in the store, the developer makes a $0.50 on an item they originally sold for $0.99. Is that fair?
If developers are willing to take such a hit on their profits at the benefit of maybe selling more at the lower price and gaining a PR boost, then we will see them moving to the $0.99 plan in those poorer performing markets.