If you had someone build custom cabinets for your house, would you ask how much the wood cost?
I’m not trying to be smart, just pointing out that there is a lot more to a professional installation job than raw materials. There are lots of factors that affect the cost of a roof.
I can’t speak for everybody, but I have a formula based on materials, total squares, pitch, shape of roof, ventilation, walls and chimneys that need to be flashed, etc. I don’t even like giving a total “per square” price. Every roof is different, and material cost is only one factor. From time to time, I provide a breakdown (inc. material costs) for some insurance work.
If somebody really wants to know, I will provide material costs to them(you can also call the local roofing distributor or lumber yard and get costs yourself).
One reason I don’t just offer the material cost unsolicited is that many homeowners look at the total quote, subtract the material cost and say, “I can’t believe you’re charging me X dollars for labor. Surely you are only paying your guys Y dollars per hour. You’re making a fortune off of me.” What the typical homeowner doesn’t understand is that legitimate roofers have tremendous overhead that needs to be figured into every job. We pay liability insurance (which can be a few thousand per month), worker’s comp insurance (for me around $.50 for every dollar paid to laborers), trucks, equipment, advertising, salespeople, office staff and equipment, etc. On top of that, we all attempt to make some profit.
If you want responsive service, a reliable company, and a labor warranty that actually means something, you will be dealing with contractors that have to cover most, if not all of these expenses.
I hope the explanation makes sense. Again, if you really want to know, call your local distributor or lumberyard, give them a list of materials, and ask for a quote. They will be happy to provide one for you over the phone.