I am buying my next copy of Windows. You can get a copy really cheap now if you look hard enough (less than $100) through MSDNAA or through another student organization. For me, peace of mind is worth the price.
The discount is a nice thing for students, but there are plenty of non-students in the US and especially other parts of the world where dropping a few hundred dollars on software that makes their computer work is a major burden.
Given the large distribution of the Windows OS (this isn't boutique software with a small customer base), it really doesn't make much sense that it's so expensive. If the price was lowered significantly ($50 maybe?), I think MS would see piracy numbers go down and sales go up more than enough for them to remain profitable.