Vern is right. M$'s licensing prices have always made them lots of money, so they ain't about to stop now.
This is what the whole "activation" issue is about. So you can't use the COA on more than one PC.
You can get licensing per PC slightly cheaper using bulk licenses, but it's not that much cheaper, and only available to certain customers with certain requirements.
M$ has got us all by the short hairs here.

This is one of the reasons linux is becoming much more interesting to corporate clients - you can buy one CD set, and install it on as many PC's as you want.
Cheers
Mick