When will *I* buy a 4K TV
Choose any of:
1 - When there is sufficient content that I want which is exclusively available in 4k definition. Let's say: every film release for the previous 5 years.
2 - When I need a new TV and the price of a 4k set is within 25% of a standard (2k) HDMI for the same screen size
3 - There is some killer tech / app that won't work with my existing 2K technology
4 - When I lose all sense of proportion and get caught up in the hype
5 - When 8k comes out and 4k sets are on sale and I need to replace a 2k set
Personally, I reckon that with the exception of (3) - which will never happen - these are in approximate chronological order. So the clock will start ticking as soon as all major films stop being released in 1920x1080 format. Which is probably a long, long way away.