1. A method comprising the steps of: providing a vending machine having a plurality of product dispensing devices, each of the product dispensing devices has a product dispensing location which holds the next product to be dispensed from the product dispensing device and a plurality of product storage locations which hold products to be sequentially moved to the product dispensing location after the next product to be dispensed is moved from the product dispensing location, obtaining a visual image of the next product to be dispensed at the product dispensing location at which the next product to be dispensed is located, said step of obtaining a visual image of the next product to be dispensed includes moving a carriage on which an imaging device is mounted relative to the product dispensing location at which the next product to be dispensed is located, comparing features of the visual image of the next product to be dispensed from the dispensing devices to a data base of features to determine the identity of the next product to be dispensed from the dispensing devices, and thereafter, moving the next product to be dispensed from one of the dispensing devices to a product retrieval location where a customer has access to the product, determining prices for the next products to be dispensed from the dispensing devices based on the identity of the products as determined by performing said step of comparing features of visual images of the products to the data base of features, comparing prices on a plurality of displays with prices which were determined by said step of determining prices, and changing any prices on the displays which do not agree with the prices which were determined by said step of determining prices.