Even direct from Adobe, Photoshop CS5 is only $199 if you can prove you are a student. It is the full deal Extended Edition, the only difference is you have to send them a copy of your student ID. That's $800 in savings, for the cost of a scan and email (i.e. free). It's well worth paying for it if you can. Don't have to worry about "the man."
Plus, when CS6 comes out, you only have to pay the upgrade price.
Adobe Educational Pricing