Has anyone tried building their own HID lights? From what I've read, they require a little more knowlege than usual, due to the ballast bit. I guess that they will be more expensive than a halogen setup, but can you build them cheaper than buy them? And is it even worth it? Some of the setups people have listed here, and on other istes seem to be pretty good from the reports. Is it even worth the extra hastle and expense for HID units?