The key to the better quality is not camera, it's light.
A dedicated camera with a fast lens has three key improvements over a typical webcam:
- bokeh
- less noise in the dark, better dynamic range (almost irrelevant for a webcam)
- less compressed video (potentially), which is critical for chroma keying; certain USB3 webcams can deliver a much less compressed stream as well.
If you're willing to sacrifice bokeh and don't need chroma keying, $100 or slightly more can buy you light sources to make you look substantially better on your under $100 webcam. And without proper lighting, the proper camera is useless as well.
Some other steps to look good on a webcam: choose a good lighting scheme, use proper camera settings, do some color correction; a color calibration card helps with this immensely, even a cheap one. Use the virtual webcam in OBS with a LUT generated from your card, control your scene with a vectorscope plugin. Voila, you just upgraded your look to a 100x more professional one, using just a simple webcam.
Keep in mind that you need much (and by this I mean MUCH) more lighting than you probably think you do. And possibly blackout shutters or curtains to completely block the outside light, making your lighting controlled.