I've personally have two very high end webcams from logitech and creative.
The Logitech Quickcam 4000 Pro(discontinued)
and the Creative Live! Ultra
Both are really high quality CCD webcams, and can take pictures at 1.3MP. The Quickcam Pro 4000 retailed for $100. I was lucky and picked it up on ebay for $0.99 plus $10 shipping through this guy that was selling it as-is and untested. I gambled, and I won. The webcam works perfectly.
I later was shopping for a webcam for my GF, and looked at creative webcams, as the prices for them was much lower as they weren't nearly as popular as logitech ones.
There were lots of Creative Live! Ultra webcams selling for $20-$30 shipped. This is much lower than their $50 street price.
When I finally tested the creative, I was blown away by its quality. It's light years ahead of logitech in quality. The colors, clarity, resolution, and it comes with a nifty wide angle lens to boot.