When do you stop stocking up on items for your pantry??

Here is something to consider!!  Just how full does your pantry have to be before you stop looking for bargains?  That is a question our daughter asked her father when he told her to bring home some more tins of beans on her way home from work! She pointed out to him that there are already 7 cans down there.  So what do you think is a good cut off amount when you are stock piling your pantry??