Although not used you can find cheaper projectors.
http://www.google.com/products/catalog?q=projector&show=dd&cid=2255774066529792332&ei=e3SZTPSdE5PijASNnb2bCw&sa=title&ved=0CEUQ8wIwBDgK#p
http://www.google.com/products/catalog?q=projector&show=dd&cid=1620626660021237529#
They run about $170, but being small cheap projectors they arn't very bright. You would need a dark room with no lights on. A decent over $400 projector will shine at over 2000 lumens letting you use it in a dim room (daytime inside with only indirect light). Theses cheaper ones only output at about 12 lumens. So for thought comparison think cheap led flashlight vs. flood lamp.
It's do-able but not exciting.
At about $210 here is a digital camera with cheap projector built in.
http://www.amazon.com/Nikon-S1000pj-Projector-Vibration-Reduction/dp/B002KANWQ2/ref=sr_1_1?s=electronics&ie=UTF8&qid=1285125849&sr=1-1
A quick check of Craigslist shows a price range of $300-$400 for full sized projectors.
Hope that helps |