All the lenses have been taken up by Sony shooters so there's a huge excess of Maxxum bodies.
That is true, except nearly all of these were sold with zooms that aren't very popular with digi shooters. I think they just sold so darned many of these, and there are so few buyers, that the are like zucchinis in August; you can hardly give them away. I happened into Maxxum from the Sony side when I got curious about how some of the lenses would do on film.
Somebody gave me a 7000 body. I really hated the looks and operation of all this generation of cameras and didn't touch the thing for quite some time. Now it has kind of grown on me. I guess having to screw around some with modern cameras has made me a little (only a little) more tolerant of button and menu controls.
Recently the same person gave me a Maxxum 5 body. I almost refused it, even free. It is a flimsy, non-intuitive thing (unless you like full auto everything), with a crappy finder. But I've found out it is amazingly capable camera in its own way, and is now my favorite bicycle carry camera. It is so light it feels like the plastic packaging for for something.
Some of the zooms are good too. Like the 35-70 f4 that you can get for under $50, The only trouble comes from how few fast primes (except 50/1.7) were sold, making them disproportionately expensive.
And, of course, the retro thing is a factor. I have a Nikon 6006 which I think is really a better camera than an FM, if you want autowind. I tried to sell it here and couldn't get $25 out of it. Ditto the F80 I can't sell at any price; not a camera to substitute for an FM, but a spectacularly nice camera of it's kind.