FIELD: computer engineering; buying products (goods) using special price discounts. SUBSTANCE: system has customer's card identifying unit, source data array memory unit, data base archiving unit, goods price-list reader unit, data control and processing unit, commodity price shaping unit including current discount, new discount shaping unit, and sales register. Method using this system provides for shaping new discount for newly purchased goods including previous discounts. EFFECT: provision for offering special discounts progressively increased with every new purchase. 6 cl, 2 dwg
