We buy a LOT of Stone kit (new) at work, and it it survives a secondary school setting reasonably well. I got the SmallestCub a second hand HP laptop from their refurb shop last year and it was cheap, in good cosmetic nick as described, arrived very quickly, and has worked uncomplainingly since. My current work machine is a 2016 Stone laptop and it has got a bit flaky in the last year or so, having been used so much that I've worn a fair bit of the lettering off the keyboard... it's getting replaced imminently (well, when I get round to sorting it out) with another Stone. My much-more-bothered-about-the-Shiny colleagues who have actual desks and a place of work all have higher spec stone desktop machines to run their very many monitors each, and are happy (insofar as an IT team is capable of such) with 'em.