You would have to find the surface areas of each box, which would be 8*4 *2, 8*3 *2, and 4*3 *2. That *3, would be the cost, and then surface area of 2 would be 12*4 *2, 12*2 *2, and 2*4 *2. That *3 would again be the cost to make the box. That all would be A=64 + 48 + 24, or 136*3 = $408 to make box A, and box B=96 + 48 + 16 = 160*3 = $480 to make box B. Therefore, box B, or $480 - $408 = $72 more.