Check this out http://www.engadget.com/2013/04/12/seiki-50-inch-4k-1300/
This is an off brand,but I have owned off brands that are still going.
The TV's I still own are a toshiba 37 inch 720p ,I paid 799.00 for it, also own a 32 Olivia,paid 1000 and a Polaroid 19inch,all of the TV's are still going strong.
I also own some high end TV's, Samsung 81F 40 inch LED Local dimming 1000 and a LG LV 9500 55 inch nano LED local dimming 1500 .
So you see this 4K TV is in my price range and all the off brands TV's I have are still going.
I believe the panel is made by AUO which is making panels for sony.