orihS Shiro, you give some pretty good advise on low and mid-range systems.But when someone wants a higher-end PC your still trying to set them up with a mid-range. A cheap mobo on a lower-end system isn't going to affect system performance much. Cheap mixed with cheap is a good match. But with a higher-end system you want to avoid cheap, this doesn't mean you have to buy the best most expensive stuff. If the OP was wanting a $1200-$1500 PC I could see downgrading to a cheaper mobo, but I wouldn't. I would recommend slower memory or a smaller hard drive or anything that is easier to upgrade later 1st.
Edit: And there are Solid Capacitors that are not Conductive Polymer Capacitors. There is a difference but were back to the Higher Quality stricter Specifications aspect.