Most pirated software is a risk, but overpricing like this just encourages piracy.
There's a reason PC games normally retail for less than console games, and that's because they have a much lower trade-in value, especially games like this that require activation. From what I've read, Blizzard are intent on screwing even more out of their Starcraft fanbois through online extras, not too mention generating advertising revenue at the same time.
Clever old Blizzard, but not for me. Much as I enjoy RTS games, I'd just feel ripped-off forking out over thirty sobs for a PC title.