Microsoft has a licensing program for .edu that doesn’t require an “embedded” hardware license. There are also many places using Neverware to provide Chrome desktops while using the some warranty services, etc that they have with PCs.

If you buy alot of computers, you can get desktops crazy cheap. Big enterprise buyers get low-spec desktops for ~$225 without windows or $300 with. If you don’t care about power/footprint, they are the best value thin client. Schools are huge PC buyers, some districts have >300k students, so you’re easily talking 40-70k PCs annually.