bought 4 of these and had them shipped to my door for <$50:

http://www.amazon.com/Equivalent-180...dp/B00079UHDY/

all 4 are working very well with no signs of a "dud" yet.

http://www.sterlingtek.com/

I've bought batteries for several cameras from these guys - work a treat at $12 a battery.

Been using them for > 1 year without any problems.