An apparatus and method for displaying the weight or cost of segments of an irregularly shaped item involves passing a sensor bar supported above a supporting surface over the item lying on the surface. A compact hand-held embodiment of the sensor bar enables the operator to move the sensor bar in various linear or non-linear motions over the item surface as the sensor bar moves laterally across the item surface while the sensor bar support posts remain in constant contact with the supporting surface. The sensor bar contains one or more sensors which generate signals corresponding to the height of the item as the sensor bar traverses the item. At the same time, a displacement detector arrangement generates signals corresponding to displacement of the sensor bar relative to the support surface. These signals are processed in a signal processor to determine the volume of an uncut segment of the item lying behind the sensor bar at successive positions. Each of these cumulative volume determinations may be continuously converted into numeric weight values based on the density factor for the particular type of item, whereby numeric weight and cost values (based on weight) are continuously displayed as the sensor bar is stroked over the item, thus enabling the operator to accommodate an on-looking consumer's specific requests as per the particular portion desired based on the physical appearance, weight, and cost of an item before the item is cut.