A torch on roofing system costs about $1 to $2 per square foot (the average price is around $100 to $200 per roofing square). For a torch on roof made with low-cost budget roofing material, expect to pay $365 to $460 per 1,200 square feet. If you choose high-grade roofing products, you’ll pay about $850 to $1,075 per 1,200 square feet.