Really? I've never seen one that cheap. Mine cost me nearly $50.
Here's one for a $1. These things are the only thing I use when I travel. Why carry around 4 or 5 proprietary chargers when I can just carry one that works for all the batteries I have? You can also find them anywhere on the planet for under $2 in markets. I've had one or two break on me while travelling and thus needed replacement.