FIELD : numerical devices and methods, data processing equipment. SUBSTANCE : device has database with prices for real estate items, unit of data processing, memory unit, which stores cost and location of real estate items in current calculation cycle, memory unit, which stores cost and location of real estate items in previous calculation cycle, memory unit, which stores costs of building of real estate items. EFFECT : objective assessment of costs within real estate market. 2 cl, 2 dwg