unfortunately, rechargeable Li-Ions for cameras are all about that much in price.
Ebay is a good place to look.
I've got a couple of "Canon OEM" batteries for my camera. They cost me like $6 but they work really well. i know Canon says not to use em but I've been using them for nearly 2 years w/o any problems. Of course, Your Mileage May Vary.
you can do a search for the battery name on ebay and it should pop up if anyone sells em.