I've long been searching for a simple display to show various things on HA. I wanted it to be cordless with wireless updates, small in size, and without extra sensors since the values to be displayed are already in HA. It's been hard to find something that matches all that, at a reasonable price.
I just stumbled upon a Reddit thread (since removed), where someone recommended OpenEPaperLink and this seller on Tindie. An access point for $35. Five screens (2.9" or 1.54") for $25; a 4.2" for $20. (It seems many have been looking for the same thing. The seller quickly ran out of stock, but more is on the way; more info at the link above.)
There's a HA integration via HACS.
You'll find my example of an automation that updates humidity and temperature here.
It was easy to get