1 Architectural asphalt roof shingles cost, on average, cost around 20 to 40 percent more than 3-Tab shingles, or $2.50 to $5.00 per square foot installed ($3,750 to $7,500). 2  High end architectural shingles, however, could run as much as $6 to $8 per square foot installed ($9,000 to $12,000).