A system having a device for assisting a purchase, incorporating: a central portion; suspension arms which are connected to the central portion and extend on either side of the central portion, the suspension arms being intended to be connected to a portable container which is provided with an opening so as to allow the portable container to be carried by the device; at least one movement sensor which is configured to detect a movement through the opening of the portable container; at least one image sensor which is configured to detect at least one image of a scene at least partially covering the opening; a position sensor which is configured to determine the current position of the device in a point of sale.