I guess it depends on what you need in a TV.
Under a certain size, you could always go with a computer monitor, but those are only really marketed for up to 32"-ish.
Commercial TVs typically have all the “smart” features ripped out as they’re normally just placed in a window with a media hub strapped to back. I used to install these and they never were connected to the internet as the media hub was instead connected and just fed looping slides over HDMI. Usually about the same price as normal TVs, but might be called “professional” or “signage” display.
It sucks that many TVs now have a persistent “continue setup” prompt if you don’t connect to the internet. You may need to check the manual “troubleshooting” page to see if there’s a way to clear the prompt permanently.
Edit: Sorry I totally glanced over the section where you mentioned Commercial TV prices are too high. I have seen them at somewhat reasonable prices, but they are generally not as competitive due to being niche. This one seems OK, but you may find used ones online.