Doing projections well is not an easy task, and as you discovered, it is not cheap. Your search for an inexpensive projector is likely a search for a unicorn! A cheap projector probably doesn't have the lens you need, and may not be nearly bright enough. I don't mean to be negative, but it's just a fact of physics. Picking a projector requires measurements of the physical space to figure out the right lens and brightness. The large projector you rented likely came with multiple lens options which makes it very flexible.
You may be able to find an existing projector in your district that can be re-purposed. But again, don't count on it working well. Give yourself plenty of time to make adjustments. Don't plan on just using Powerpoint for your projections. I would suggest you use QLab by Figure 53 software. It really is the industry standard, and gives you the ability to work with your video or graphics files to make them perfect. You might be able to get away with the free version, but if not, the licenses can be rented for just $5.00 per day, which then applies to your purchase if you decide you want the software forever.
Hope this is helpful. I'm happy to answer any other questions you might have.
kdl
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Kirk Longhofer
Theatrical Sound Design, Audio Production, Editing and Engineering
Systems Design and Consultation
www.technopraxis.org
kirk@technoprasix.org
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