Shop Improvements: Metal Halide Lamps

About three weeks ago I added a second metal halide lamp to my workshop. For those of you who don't know metal halides are High Intensity Discharge lamps which, in principle of operation, are nearly identical to the ubiquidous Mercury Vapor lamps. The only real difference between MH and MV lamps is the gas that the arc tube is filled with. Mercury Vapor lamps contain only native mercury (and a small amount of argon to aid in arc starting), which when ionized emit a bluish-green ligjt. Metal Halide lamps contain a variety of metal halides (the compounds of various metals and corrosive halogen gases, such as chlorine and bromine), and, when used in combination, emit a white light.
I had previously had a single 400 watt MH lamp for the entire shop which, though satisfactorally bright, made the lighting extremely directional. I purchased this second MH lamp from the Big Buffalo Pawn Shop and, upon installation, both evened out the lighting and made the working light level more natural (and therefore pleasant). I purchased this lamp for $50, they retail (with the reflector assembly) for almost five times that!
Below is a picture of my shop with both lamps operating (I removed the reflector from my new lamp, the celings are too low for me to use it). Though it may seem excessively bright in this picture bear in mind that I make my living in a room (About the same size, if not smaller) with THREE of these lamps, with white-painted walls (unlike the unfinished OSB in my shop) and there I honestly believe that I could use a fourth lamp!
Despite using 800 watts of electricity I think I now have the proper amount of lighting for a shop my size. And despite the cost of both the fixtures and the bulbs (also almost $50 apiece!) I believe that this is a cost-effective approach: For what I have spent on this lighting system I'd be hard pressed to get a half dozen high-quality shoplights and bulbs, which would in no way equal either the quantity of light or it's quality...