Sounds like a good way to make use of old eMachines, at a large discount too.
Finally, the year of the Linux Desktop! (eMachine edition)
That depends on their setup.
Taking donated PCs to save them from e-waste. Hooking it up to a large KVM and running hardware diags then a image script to load OS, software and quick check for drivers and functionality...
Maybe 15-30 min labor if you're efficient and doing them in bulk.
... Yeah still a good deal haha.
I used to do this kind of work. With a wall of monitors mounted and PCs below. It was pretty chill and just needed to poke one when needed.