You might watch ebay. Sometimes artists and graphics people will sell their old units there. The issues are volume and quality. The demand for these scanners is low, so the volume is low, so they can't spread the costs out across a high volume of scanners. Also, people who want these scanners demand a better/higher quality machine (more durable too), so the production and component costs are higher.
Have you though about a good digital camera and lens combo along with a decent lighting setup? That may be your best approach.
Doug
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www.BetterScanning.com