材料原價=32*250+31.5*680+31.2*900/250+680+900=31.42元
平均裝卸費=0.8*250+0.95*680+0.85*900/250+680+900=0.88元/㎡
運輸費=1.2*250+1.8*680+2.4*900=2.01元/㎡
損耗費=（31.42+0.88+2.01）*1.5%=0.51元/㎡
運雜費=0.88+2.01+0.51=3.40元/㎡
保管費=（31.42+3.4）*2%=0.70元/㎡
材料單價=（31.42+3.4）*（1+2%）=35.52元/㎡