I'd like to get my hands on to legal Windows XP keys so that I could setup a few virtual machines. I'm a software developer and this would be greatly useful.
I'm willing to buy them (cheaply) if needed but I've not been able to identify a source for legal Windows XP keys. Is it possible for a previous user to resell Windows XP or is this against Microsoft's terms?
I am aware of MSDN Subscriptions, but I was hoping to keep this entire project within $50 (USD). I only need two to four keys...
(Note: The legal portion is extremely important. I don't even want to be in the gray here...)