You can save a lot by not buying Coke and other forms of junk food at all. Saves
money on healthcare as well.
This author is shortsighted if they think "stockpiling" food is
wasteful. It's better to buy extra stuff at a discount now than not to have
any if it's later needed.
@infoman: I think the writer meant not to stockpile items just because they are
a good deal. If you don't use/eat/drink said item and it just sits on the
shelf, you are not saving, but wasting money. However, if it is something you do
use, then the purchase is ok.