That display out will be hard to match with an old optiplex or laptop, but I agree, the pricing is getting less absurdly low and more just moderately low.

Since you mentioned darktable I assume you already know this, but depending on the camera’s raws and the presets that imagemagick has for converting these photos the results might be undesirable if not inspected or tweaked. Not disparaging any advice given here, just mentioning that generally raws are edited on a case by case basis to fix camera artifacts and color issues. Hope the solutions others have posted work out for you!