Not sure if the question is specifically historical, imho.
Wouldn't a Kindle Matcha costs like around 150$?
An used Switch is lower that that price too, so I don't see the waste, sorry.
Others, just as ideas:
As aspect ratio a Cowon X9 (
https://www.cnet.com/tech/mobile/cow...out-now-in-uk/ ) might be an interest, but's 4.3-inch.
4.8" was a predecessor Cowon V5 HD PMP