Hey, I'm not gonna vouch for the quality, but if you're desperate for a 4K TV and you don't have a lot of money to spend, you might want to check this out.
It's a Signify 55" TV. Resolution is 3840x2160 and it's a 120Hz LED backlit LCD. It's almost certainly mediocre at best.
You might want to get it quick though, stocks are limited.