Wing Commander F, if you talk to your computer spares place and mention OEM XP, it works something lke this.
If you buy a piece of system hardware, (not peripheral though) you qualify for a Windows OEM disk. I did it with the PC on which I type and got an OEM XP Pro for a lot less than the full retail version. To qualify, I bought a new hard drive which was my real need anyway. The disk came shrink wrapped and minus the box, but has performed as flawlessly as one can expect of a MS product.
The reason that such deals are there is for those building their own PC, where inclusion of the full price retail package would make it non viable. If in any doubt, PM me and I will research more.
Conan
PS I also got an OEM Norton Internet Security 2005 a few months ago for all of £16.