https://www.sony.com/electronics/digital-paper-notepads/dpt-...
https://www.theverge.com/circuitbreaker/2017/4/10/15242238/s...
It's $700. Also, it can take input from a stylus to annotate the documents on it. But otherwise it's what you want. I, too, wish there were cheaper options for this purpose - even if it was a thick, heavy monitor with a stand and built-in 120V power supply rather than a tablet (though I suppose the power characteristics of e-ink displays mean that the economics will typically prefer the tablet form-factor). Reading is just a lot more pleasant on an e-ink display.
I also thought they were going to be jumping to Android 6, but the site still looks like all 4.x.
http://onyxboox.com/product#lineup-5
Looking at the linked online shop, 9.7" is ~$380 and 13.3 ~$800