I've got rather a lot of folders, after a hunt in the loft at the weekend I 'discovered' quite a few I'd forgotten about!
So far this month I've put a film through a Voigtlander Perkeo, Agfa Silette II and Zeiss Ikonta. The Ikonta wins hands down on optical quality, not a fair comparison as it has a Tessar wheareas the others have cheaper lenses, but it also seems to be ergonomically the nicest to use and seems to have stayed in better condition. It has all of it's leatherette still intact, has smooth focussing and aperture and nothing leaks
The other two are the same vintage but don't seem to have stood up quite so well. Obviously, they may have had a harder life...
The Agfa seems to produce great images, despite looking a little battered.
The Perkeo looks very nice, nearly as good as the Ikonta except it can't seem to keep it's leatherette on... but alas this camera is incapable of taking a sharp picture. I don't know why yet, I suspect it isn't typical, many APUGers have rated the Perkeo very highly, but alas mine is a lemon
Two I haven't tested yet are a brace of Agifolds. One is the most mint, pristine, 'looks brand new' folding camera I've seen. It's beautiful. The other looks like it was fished out of a canal. Rusty, battered, paint missing, leather coming off, fungus in the optics...
My point is that with cameras so old, condition is everything. I think mostly all of them can give a good account of themselves if in good condition.
Many of the cameras with the better lenses command a higher price, much higher still with built in rangefinders and meters. I personally think the huge hike in price is not justified by the modest advantage of built in widgets. Any lightmeters will be useless now, anyway. They are best left to the collectors. You can easily pick up a flash shoe fitting rangefinder. If you can get a high spec Ikonta under $100 I'd be suspicious, it is probably not a good buy, but you could get a very basic spec Nettar for well under half that in absolutely mint condition. If you can get a mint basic spec camera with a 'one up from the basic' lens on it, you are onto a winner.