Slide projector as light source . . .

OK, I've read the small projector thread, but I'm not wanting to cram a LCD down into the projector. Why? Because I want XGA quality. Anyway, I have a slide projector with a 500w bulb of some sort (hey, it's bright). So, would it be a good idea to use the whole slide projector as a light source since it's already even lighting?
 
200 hours if awfully short life span. MH avg. around 15,000 for $20.00+ that we are using. The reg. projector use $300-$500 bulbs and avg. about 2,000 hours, the dif in bulbs. Some have built in reflector for the bulb and also have very short arc gaps for a closer to point light source therefore making the reflector more effective at making parallel light beams.. A slide projector bulb is very hard to tell how much money per bulb cause they are all so dif. but at that rate of life you will be changing bulbs very often. Even with cheapo bulbs that will add up quickly.