To provide a DC power supply system to stabilize voltage of a DC bus to which a DC power source device is connected.
Commodity information on regular sales commodities and limited sales commodities whose sales quantities are limited are stored in a commodity information storage part. Commodity information on each of commodities to be sold is acquired. It is determined whether a sold commodity is one of the limited sales commodities stored in the commodity information storage part based on the acquired commodity information. A quantity of the limited sales commodity sold to a single customer is calculated by using customer information acquired by imaging the customer who has purchased the commodity and the quantity of the commodity which has been determined as one of the limited sales commodity. It is determined whether the quantity of the limited sales commodity is less than a prescribed quantity, and when it is determined that the quantity is less than the prescribed quantity, a special price is applied to the sold limited sales commodity for settlement.
Masanori Akiyama
Shinji Kai
Yusuke Kaneko
Kiyoshi Inamoto