I've made a front projector for <$200, and the bulbs don't cost $300-400 each either
All I did was put a LCD panel on top of an overhead projector. Is it glamorous and high-def? Nope. But it gets the job done, and it's a lot of fun playing XBox games or computer games on an 80"+ screen.
Now I want to build my own high-def unit. Hundreds of people are building their own using disassembled LCD monitors and throwing a bunch of optics and lighting together. Check out
http://www.diyprojectorcompany.com/ and
http://www.lumenlab.com/. For $600-800, you can build a unit that's higher resolution and cheaper to run (bulbs last longer and are < $100) than commercial units. Best of all, it's completely upgradable because you built it, and you can easily switch stuff around.