Another idea is to regularly check Craig's List for people selling their cameras. I got my current camera from there. Keep checking CL for a few days. Whenever someone posts what looks like a good deal on a camera, google the model name for reviews and prices. Amazon has a lot of consumer feedback to read.
If you see something fantastic, jump on it quickly. I got my Canon PowerShot A300 and three memory cards for $60 used. The A300 has nice picture quality, but no optical zoom. If you can't or don't want to go the CL route, try trading with someone on a forum that you trust enough. I'm a big fan of used for midrange digital cameras, since I'm a college student and I've had good experiences with used products.