How big is your TV?

Our 55 inch Sony Bravia 4KHD was 975 bucks new 2 years ago at Best Buy. I do shop at Warmalt. I bought the screen cleaner kit from there LOL.
During the past Christmas season sales, 55 inch 4K smart set tvs of various brands were offered at about half what I paid.
I'll assume you are looking at the latest and greatest, a curved UHD.
The consumer report like independent testing I've seen says the difference in 4K and UHD/ultra high definition cannot be seen with the human eye unless you're viewing small portion of the screen at about 1 to 2 feet away. So in reality, "U" is only a industry sales gimmick.
Search YouTube, 4K versus UHD. The only mystery is what will they call the next so called improvement. Actually 1 change, upgrade or not, is here now... OLED. The "O" stands for organic, meaning environment friendly. WTF? they're using fire flys? I aint done that research. Hope I don't need to for several more years.
Also consider this... the signal received makes all the difference. Our same single layer DVDs in the same old DVD player didn't look a lot better than before on the 42 inch crt, just bigger.