You have to break through a wall so you can approach the checkout counter from the wrong direction. But once you do it the cashier will give you $30 in "change"

You have to break through a wall so you can approach the checkout counter from the wrong direction. But once you do it the cashier will give you $30 in "change" without you ever having paid! Only problem is when you leave you end up back in the entrance to the store, until you die.