Unfortunately, because of the short supply of graphics cards, it’s going to be extremely hard to find a computer under $2,000 that is good for using with Unreal Editor. Unreal Engine is a top level real-time performance system, and requires very beefy hardware to run the production path. That’s just how it is. If you do not need top-level graphics with real-time performance, it’s much cheaper to go with some other solution to visualization and animation.
The most important parts to look for are: Graphics card that’s GeForce RTX 3070 or better, or a Quadro RTX A4000 or better. Fast NVMe drive, ideally 2 TB or bigger. 64 GB or more of RAM. (Recommend 128 GB.) Many cores on the CPU.
Again, you just can’t get anything below $2,000 here, because of the graphics card pricing problem. You can get a RTX 3060, with too little RAM, and too small a NVMe drive (or a 7200 RPM spinning rust drive, which is right out) for about $2,000.
Other info: Some people have had luck with Radeon graphics instead of NVIDIA. Unfortunately, they’re not a lot cheaper, and some people have less luck with them, so make up your mind on what you want there. Laptops generally give you less performance for the same money, AND are harder to upgrade, if it can be done at all, and they generally “top out” sooner, both in how much memory/disk you can put in them, and in how fast they will run before thermal throttling. I recommend against laptops for the use case you suggest.
I realize that I should probably give some links. Try these links (although you’ll want to upgrade them somewhat):
Also, there are perfectly fine AMD Ryzern/Threadripper options for the CPU as well. They tend to use more power, but have more threads, which generally helps when working in Unreal Editor.