I have a couple Samsung Galaxy A8 (2022) tablets set up as control panels around my apartment for Home Assistant. They cost a little more than $100 on eBay in very good condition. I don't think LineageOS supports this particular model, though, but I didn't bother since all it does is display a webpage.

One of the things I like about Samsung tablets is that they have a "Battery saver" feature where you can restrict it from charging the battery past 85%, which is a generally good move if your tablet is going to be permanently plugged into power and used as some sort of fixed display.

I've had MANY brand name devices with lithium batteries bulge when left constantly plugged in at 100% battery for months and don't want to risk an explosion.