I've been using "cheap" 43" 4k TVs as my main monitor for over a decade now. I used to go purely with Hisense, they have great colour and PC text clarity, and I could get them most places for $250 CAD. But this year's model they switched from RGB subpixel layout to BGR, which is tricky to get working cleanly on a computer, even when forcing a BGR layout in the OS. One trick is to just flip the TV upside down (yes it actually works) but it just made the whole physical setup awkward. I went with a Sony recently for significantly more, but the picture quality is fantastic.