an expired Chromebook and Ubuntu

Walmart sells cheap janky tablets under the Onn brand. I think you can get one for like $50. May be better off getting a nicer used tablet for around the same price off Marketplace or craigslist. The walmart ones are real shitty lol

If you're intending to purely stream games or something along those lines, you might want to look at one of those really cheap Fire tablets, new or used. They clearly are intended with planned obsolescence in mind unfortunately, but as long as you get one from 2015 after, you probably shouldn't have any issues with app compatibility. Do note that if you plan on rooting or installing Linux, they aren't that great of an option as their process is strange and complicated.

In terms of running Linux on, there are a few Atom-based cheap 8-10 inch tablets from Dell and other manufacturers that you can buy for dirt cheap used, and they could probably serve your purpose quite well.