oh ok, so not the chipset. I dunno man, 3 things here:

1) I really REALLy doubt you could build a comparable computer for the same price. Maybe though, but especially at levels below that, you simply could not do it cheaper by yourself than walking into a store and buying one already made.

2) Let's face it, for real world computing, the type of person that would purchase a computer at best buy would most likely never notice any shortcomings in the motherboard. I say "most likely", but I feel this is a fair assessment having built numberous computers and worked at a computer retailer.

3) Building your own computer is not for everyone. Especially if you haven't done it before. If you can't definitively say WHY you are building your own computer, I really don't see the point. I built mine, but only because I wanted an uber leet machine for gaming.