The cost of XP is right up there with good DDR.
Sure, but the white box builders probably don't offer a decent amount
of high quality RAM as standard. I believe the hard disc is the most
expensive component (after Windows) of an entry-level PC. Nearly
every other bit of hardware is integrated with the motherboard on
this kind of system, which is built down to a price point, not up to
a specification.
Cheers
Daniel