graze and pay
Eating food in a grocery or other food supply store before paying for it at the checkout register or other payment accommodation under a similar mind set as going to a sit-down restaurant and paying after the meal is consumed. (Some stores such as Wal-Mart Neighborhood Markets make it easier to pay first by providing a dollar or half dollar price and a "pay here" box for coffee and a donut or a sweet bun.)
Man its been a long bike ride. I need to go into that Walmart and do some graze and pay or before I die of starvation.