So now the businesses that supply you your supplies raise their prices due the their cost of operation rising. The cost of heating, cooling, running stoves/ovens, refrigeration increase because they have to double their worker wages Your meat/bread/veggie/ condements prices go up due the the cost of your suppliers costs rising and any delivery based services(labor only) rise because they have to double their employee wages so their price goes up. A vicious cycle of inflation.
Now you have to double your sandwich price