My 25pk of surefire CR123A's has a supposed shelf life of 10 years. I don't know what you consider to be "bulk," but I'm planning on buying 100 when I start getting low.
Just be careful which batteries you use. A friend of mine works for a battery vendor and he told me that certain CR123's will over heat when used in flashlights, some to the point of melting. I stick with the surefire brand batteries in all mine.