> So there is a market gap between so-so webcams for $100-200 and a full-blown setup with a mirrorless camera, an external mic and lighting panels that will cost almost a grand or two, if you're so inclined.

Nope. You can get a mirrorless camera set up (with mic and lights) for around $500 to $600. There are plenty of 1" compacts as well in that price range.