Mariano, from the selling side I never ran that arithmetic. My buyers ask for origin paper, preference or not. The cost was never mine to decline.
The cut changes the exposure, not the cost. A preferential claim is the one tested later, and the duty comes back long after the cargo is gone. In my market the buyer comes to me for it, so a thin saving buys a tail.
What made my paper cheap was one statement for a season, not one per shipment. Certified per consignment by an authority, that is cost per tank.
