The average cost per sq ft depends on the materials, but this is close to what an official estimate would look like: - Asphalt shingle (3-tabs): $3.00 - $3.75. - Asphalt shingle (Architectural): $3.50 - $5.50. - Corrugated metal: $6.50 - $8.50. - Standing Seam metal: $9.00 - $12.00. - Aluminum roof: $4.00 - $5.00.