The 'mate's right - it's hard to judge these things without the appropriate measuring devices and personal credit check. But my husband and I are having our roof replaced next month - just paid the deposit last week.
I don't know the size of the roof, but the house is roughly 3,000 square feet + 2-car garage; colonial style with hip roof. Timberline brand 40-year shingles in pewter gray, with the appropriate ridge vents, moisture barrier, etc., will set us back $11,900 U.S. (includes installation & debris hauling, but surprises are extra).