Providing a web site that gives subscription based computer users the ability to check availability and pricing of retail store products that may be purchased for resale in the user's stores according to pricing strategies and rules established by the user, and according to availability, the ability to access and receive information regarding deals and other information supplied by the product vendors, the ability to make product purchases, the ability to verify invoice accuracy, the ability to learn of price changes in advance of the actual changes, and the ability to generate labels, tags, signs and other advertisements based on available product information; providing a web site that gives subscription based computer users the ability to allow product vendors to upload new products, price changes, deals and other information regarding the availability of products that may be purchased by retail store users; Providing temporary use of on-line non-downloadable software for maintaining a database of multiple vendor products, prices and availability; providing temporary use of a web-based software application for accessing and receiving information regarding the availability and pricing of products that may be purchased for resale in the user's stores according to pricing strategies and rules established by the user, and according to availability, for accessing and receiving information regarding, deals and other information supplied by the product vendors, for making product purchases, for verifying invoice accuracy, for learning of price changes in advance of the actual changes, and for generating labels, tags, signs and other advertisements based on available product information; providing temporary use of a web-based software application for product vendors to upload new products, price changes, deals and other information regarding the availability of products that may be purchased by retail store users