Interesting discussion. I believe that I can get an original unused (sealed) copy of Win7 (I don't know which version - probably the basic one) in England for around GBP70. That doesn't make Bz$300 for one of dubious legality sound very attractive.

In any case, starting with Vista Microsoft are getting much better at spotting pirated software. I have little doubt that a pirated copy of Win7 wouldn't work for long.