The average cost of new residential metal roofs is $5.50 per square foot of roof material. This is the average price per square for metal roof of mid-grade quality. A low-grade roof costs around $1.40 per square foot on the average.Some materials of high-grade quality are around $12 per square foot.Thus, the cost of new metal roof would range anywhere from $3,400 to $28,000 for a total area of 2,500 square feet.Keep in mind, the cost of material installation or removal is not yet included in these figures.ome materials of high-grade quality are around $12 per square foot. Thus, the cost of new metal roof would range anywhere from $3,400 to $28,000 for a total area of 2,500 square feet. Keep in mind, the cost of material installation or removal is not yet included in these figures.