The challenge with any technology investment is that it becomes obsolete very quickly. This year's $2000 computer is next year's $1000 computer. It's not always a wise investment to chase the latest technology or spend as much as you can. My rule of thumb has always been to spend no more than $1000 on computer. (We're talking only about the box, not the monitor, etc.) That way it won't break your heart in a year when you find out it's only worth half as much.

The good news is that you can get alot of power for $1000! Certainly enough to edit 4K and way more than enough to edit HD.

Although laptops are a bit different. For one thing, you can't just buy the CPU unit, so a lot of what you're paying for is the monitor. Also, laptops are built for portability rather than speed. So a laptop won't run quite efficiently as a desktop with the same configuration. But as fast as today's processors are, that's not as big a deal as it was. Just know you're going to significantly pay more for a laptop than you will for desktop with the same guts.

With thousands of possible configurations out there, I recommend using these benchmark numbers as a measure. A rating of 10,000 for a CPU is very good. 15,000 or more is excellent. That and 16 gig of RAM or more will take you about 90% of the way there, if you're editing with PowerDirector.
https://www.cpubenchmark.net/high_end_cpus.html


Picking a graphics card is a bit trickier. But you'll find a listing for video card benchmarks also on that site. With graphics cards, it's more than simply a high number. A video editor doesn't need the same GPU as a gamer. So with graphics cards, it's best to get a recommendation from a fellow user.

But focus first on your CPU, IMHO. That's the engine that drives your computer.