See my previous comment:
>That doesn't mean it's suddenly worth doing unless you can make the argument that it scales easily.
Otherwise it's like saying "you know what everyone should do? Raise their own chickens! Sure, you might be only saving $1 or whatever a day, but multiply that 365 days per year and 340 million Americans, and that's billions we're all collectively saving!"
And no, running a grocery store isn't something that scales easily.