Does it need to be so cheap? With these specs it would make a decent replacement for a low end general purpose computer. The older NUC I use for a lot of stuff has similar-to-worse specs than this thing does.

If it’s not cheap, then what differentiates it from a $150 Linux laptop and $30 dongle

That's exactly my point! It's a low to midrange computer with extremely high portability including a grayscale display. Where else are you going to get that functionality combined as a single unit?