Under item details, you may enter a number in the price field. It’s used to remind the person shopping what the price of the item should be.
If you mark the items as bought at a location that has been identified as a particular store, the system knows what you paid at for the item at that store. Every night, the system traverses purchases made during the day for frequently bought items. The crowdsourced prices are inserted into the global price list available from the menu.