I do too. But what you describe there is basically a monitor.
1. Is this still true that TVs are considerably cheaper than monitors?
2. Is there a difference, or one I should care about between the two?
There are differences.
Just to name a few:
Monitors have better colour accuracy, higher refresh rates, have features like Gsync/freesync, way faster response times, more and better ports like displayport 2.1 and usb c, lower input lag.
https://www.postium.com/8k-series
https://www.bhphotovideo.com/c/product/1768977-REG/postium_k...
E.g. 4k 55" for $599: https://www.sceptre.com/TV/4K-UHD-TV/U557CV-UMRB-55-4K-UHD-T...
I've also seen Supersonic and Caixun mentioned in these discussions.
Can also be worth looking at "outdoor TVs" like Sunbrite.