There are two issues to be concerned about: working height and latency. Without a fair amount of working height, it will be clumsy to get your iron/hot air wand and tweezers in. Latency on a lot of those inexpensive scopes is really bad. Anything above a few hundred mS is going to be very distracting. I have 3 digital microscopes and none of them are that good. The best was about $60 a few years ago, iirc. And I don't use it for assembly but rather inspection, latency is just on the edge of usable and working distance is just ok.
I have also built a RasPi based system with the HQ camera module. It is quite good - fairly low latency and you can select the right lens for your application. All in cost is about $80 for the camera and a RasPi 4. Lens is extra and you can pay $10 to several hundred. Good macro lenses run $50 to >$100. You would need to create an adjustable stand for it. The advantage is you can shoot high quality photos with it as well. The cheap chinese units take mediocre to terrible photos.
But, for assembly, I just use a big magnifier on an adjustable swing arm. I don't need more than 2X magnification. Great working height and 0 latency. Easy to get out of the way when I don't need it (which is about 95% of the time).
I also have an Olympus optical stereo microscope - really good but too much hassle to use.