The days of calculating exchange rates are coming to an end: over the next year Valve is looking to introduce a range of local currencies to its Steam marketplace, including tohse of Australia, Canada and Japan.
If you live in one of the included countries, your first instinct may be to celebrate. Don't. You're often getting a bargain buying things in US dollars. A Steam marketplace available in your local currency may just make it easier for publishers to charge people like Australians their regular exorbitant prices.