I wrote about this before. Now WalletPop agrees... bulk buying may not be best for you or for the environment.
However, as my buddy Shane pointed out (see comments on my other post) - if you have a long way to go to do your shopping, bulk buying may be best. Also, there is that container size issue; it's better to have less packaging. But overall, I'm in the "have less on hand" camp.
Photo from Flikr.