Used or new old is almost definitely the way to go. $50 usd still lands somewhere in the "nicer webcam with knobs on" range with respect to new construction; but can probably manage something nicer used. If you could stretch another 30 or 40 bucks, though, you'd probably be better off.
A quick perusal of Ebay shows a fair number of quite decent 2-3 megapixel point and shoot models, often with some adequate glass on the front, going for 40-80 dollars. Sure, ebay is more annoying than retail; but all you'll get for 50ish retail are models with .8 megapixel sensors and "12Megapixl Soop3r 8X Digital zoom L@@K", which just aren't worth it.