Unless you're going to a 2year school, you can buy Home and Pro for somewhere between $5 and $15 at your college. Fully functional. Individual cdroms, packaged. With instructions and msft support. Official cdroms with the pretty little holographic msft logo and cdkey.
*All* you have to do is flash your college id. Most will scan it, so if you try to buy 5 copies, they shut you down. If you're just buying 2 or 3 per semester, you're good to go. If you don't know where the campus computer store is, grab an EE geek and ask. Or go to the network help desk and ask them; some schools sell them from the net help desk.