Lithium batteries cost a hell of a lot more, but also last a lot longer, and they will work at temps a regular battery won't touch. Some of our cameras will last a year on Lithiums, but cameras are not all equal in that regard. I have one camera that eats even lithiums in a few weeks. Lithiums also provide a higher voltage, that means a better flash, and better photos at night.
I want to get some converters so I can run them in cameras that are set up for C cells. I might just wrap some in cardboard to try it.
Lithiums never seem to come on sale, but you can sometimes find online prices that are better than Canadian Tire.