Steam currently has 2K Games' BioShock going at a discounted price - about half its original. In the US, this puts it at a tidy $US 14.99. In Australia, however, it's $US 24.99. After you've suppressed a groan, consider the fact it's not such a bad price for BioShock and, if you haven't picked it up yet, now would be a good time.
BioShock™ on Steam [Steam]