PURPOSE: To attain the smooth circulation of commodities by collecting and transmitting plural pieces of media information in response to the buyer's request for decision of the commodity value and by returning the purchase decision result from the buyer side against the received media information.

CONSTITUTION: When the sea food are landed at a production center A as commodities, these commodities to be sold at auction are immediately converted into the video signals by a camera 5 used exclusively for a high-definition TV set. At the same time, the auction prices of commodities are produced in voices through a microphone 6 and inputted through a data input part 24. A controller 7 converts these video and voice signals into the digital data and compresses these data to input them to a controller 9 of a designated sea food market, i.e., the buyer side via a B-ISDN circuit 4. The controller 9 distributes the digital data sent from the production centers A and B to the high-definition TV monitors 11 allocated to the centers A and B respectively. Then the controller 9 expands the compressed signal into its original form. At the buyer side, the commodity value is decided based on the corresponding information and an answer is sent to the seller side in regard of purchase or non-purchase of the commodity.