How much more expensive is or is not Weaver Street Market?

I wonder if anyone has tried to calculate what a week's worth of groceries for a family of 1-4 people might be if bought entirely at Weaver Street Market v. driving to whatever one considers to be the lowest price option, perhaps Food Lion or even COSTCO. In other words, if you bought everything you need for a week at Weaver Street Market and bought the same things at a perceived lower price competitor, what would the price difference be?