life cycle costing

sir i dont understand why the following statement is false? "lifecycle costing is useful for deciding the selling price of a product" the text says no it is not, because depending on the stage of lifecycle the selling price can differ. but my point is although selling price may differ depending on time, life cycle costing does give us a lower threshold for the selling price and in fact even a realistic figure of selling price based on total costs incurred over the lifecycle of the product, so why is this statement false? thanks a ton as always!