Unexpected power spike, mysteriously "fixed" later = short circuit caused by a loose screw rattling around on the planar. Might be a good idea to power down the case and look around inside before it shorts out again.

Intel pricing for the quad cores is such that buying components is simply not competitive -- as the Acer at BB illustrates. Lots of other even cheaper sources (e.g. the "new" compusa.com is very cheap for quad cores if you don't care about the specific config). As for video cards, something like the ATI HD2600 is down to USD 100 now, which is quite a deal (and gives full 1080p native processing -- making your PC quite versatile as an MMC).