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You are going to have a problem meeting demand. And some for profit shop is going to use these as digital signage and suck up all the supply. Beware of unintended consequences, everyone that buys them isn't going to be doing good in the world. Capitalism is faceless and cares about us much gravity or water.
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Another option is to have a classroom in a box package where you sell 30, power supplies, keyboards and an app that runs on all operating systems so you can DD pre-canned images onto end user supplied SD cards (point them at preferred cards on newegg).