Projectors

I am currently teaching photography classes in the Adult Ed program of a local public school. A big problem is the poor quality of the projectors provided. As a result I am thinking about buying my own. Because I am not making that much money, I need to keep this cheap. I note that you can buy a 1080p projector for well under $1,000 and an XGA projector for around $500.00. They would also have to be calibrated. Is there any input anyone can give me in this regard?

Thanks
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Jim
http://www.pbase.com/jcassatt