Well, of course I'm not getting old gaming/pro laptops with dedicated gpus, they would consume far too much power, require extensive cooling, and these are way too expensive anyway, even when broken. I usually get old, boring office laptops (lenovo/dell) from bulk resellers, with integrated graphics who are sufficiently used/broken so they are dirt cheap. As long as they still turn on, the mainboard is usually fine (I've yet to get a broken one).