As reported by 9to5Mac, Apple is set to increase the prices of apps in Australia, Indonesia and Sweden within the next 3 days. The new prices will affect all paid apps, In-App Purchases and In-App Subscriptions. As an example, in Australia, the App Store pricing Tier 1 will be increasing from $1.29 to $1.49.
In an email to developers, Apple explained that the price increases are a result of changing foreign exchange rates. In the case of Australia, the above chart shows how the Australian dollar has depreciated in value against the US dollar since the last pricing change in April 2014.
Apple is also introducing the Alternative Tier A and Alternative Tier B pricing tiers to Australia. Apps sold at these price tiers will cost Australian App Store customers AU$0.99. These tiers have previously been used by Apple to enable developers to sell their apps at very low prices in some developing countries such as China where Alternative Tier A (¥1) is equivalent to US$0.16.
If you want to know a bit more about App Store Pricing Tiers, I wrote an article about them which has more information on how they operate and why Apple needs to adjust them occasionally.