This is applicable only if the item is priced by quantity of a unit. The item must have a priceType of PER_UNIT. The value is a fixed-point integer with scaling factor of 1000 (e.g. if charging per ounce, the value should be set to 2500 for 2.5 ounces). To compute the complete price perform the following calculation: PRICE * (UNIT QTY / 1000). If the item doesn’t have a priceType of PER_UNIT, then unitQty is ignored.