In my area 'Youngstown, Ohio' the average ranch style home with one existing roof and no deck, gutter or siding work needed will run in the area of $200.00 per square for material and labor.
You'll see estimates from $60.00 per square less too $150.00 per square more.
Make time to take numerous estimates from both larger and smaller operations and make sure to ask questions:
Insured, Licensed, Referrals, Utilizing Employee's or Subs 'subs insured?'
etc.
Make your final decision based on both quality and price, not one or the other.