A metal roof costs $5.50-$14.00 per square foot. Asphalt shingles range in price from $3,50-$7.00 per-square-foot. The final bill for a 1,200 square-foot metal roof averages $8,400-$19,000 and higher. Using asphalt shingles to redo a 1,200 square-foot roof costs $4,200-$8,500.