I found an article about a teacher building a computer lab on $0. That’s mostly what I did for years refurbishing whatever PCs were in storage or not being used in schools where I taught. GNU/Linux is very flexible and installs on a wide variety of machines without concerns about drivers for the particular machine since most drivers needed to boot are part of the Linux kernel.
“With the help of his local LUG, he got Linux up and running on his 18 donated machines. Suddenly, they were fast. They were clean. They worked well in the classroom. Robert was invigorated, as were his students.”
Of course there are challenges particularly for a newbie to GNU/Linux not knowing how to do much at first but it’s all been done before and Google is your friend. Apparently this guy set up thick clients which is OK but there’s nothing better than LTSP for schools if at least one decent/modern/resourceful machine is available. It’s found in several distros. e.g. Debian GNU/Linux.
It’s not difficult to get old/donated PCs in many places thanks to Wintel’s built-in obsolescence. The hard part is getting things like monitors, keyboards and mice which survive a step on the Wintel treadmill. Sometimes you just have to have a bit of money. I once equipped a whole school with fine HP USB keyboards with a hub and optical wheel mice for $10 a set. Some recyclers will donate equipment rather than having to dispose of its materials. That is a liability for a school in many places but it’s still cheaper than buying new.
Thanks to the flexibility of GNU/Linux and its licensing, schools have no excuse for not having one or more computer labs and some PCs in every classroom.