IDEA: Offer price cuts tied to cost cuts in freight / shipping methods.

When asked for a price cut, offer the customer a price cut equivalent to the drop in freight price when shipment requires several more days, or loaded on rail, or is loaded on a cheaper less than a load (LTL).  Requote the order with the cheaper freight and pass it on to the customer based upon the order size and delivery method.  Pass only the freight savings onto the customer if that is possible.