Omg, I found some old but pretty fancy mp3 player and now I'm excited but not sure what to do with it. https://computerfairi.es/media/j3oRPWDOUKICpmVVA70
It even has a sleep timer, but it makes this charming noise when you turn it off, I don't think that's ideal for a dedicated falling asleep audiobook device.
There is still an official support page for it and I'm totally doing a firmware upgrade (June 2008 instead of April 2008!!) as soon as it's charged a bit, but then? Maybe I can use it as an exclusive falling asleep audiobook device o.O