The little Dinolite USB microscope I have is capable of a nominal 50x and 200x, but it's front lit, so not suitable for the classical biological slide work. I bought mine predominantly for examining metal surfaces (fracture and wear surfaces) but its interesting to look at all sorts of stuff.
I bought mine some years ago for $160, but the same thing now would be considerably cheaper. Its much easier to move a little USB microscope to a 25T piece of machinery, say, than vice versa
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I'd love a nice microscope, but I'm not sure how much I'd use it given the things I'm interested in. I hope you find a good one with a camera port
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Al.