If you bid by the square foot, you'll lose.
If you bid by the device, you'll lose.
You'll not be fair, or cost effective except to the GC. He in turn will markup by an astronomical amount, negating any impact you might have on "fair" or "cost effective".
How do you think the GC makes HIS money?
You are getting sound advice in the 2 above posts, if you choose not to take it, you'll lose.
Know your cost of doing business, and go from there.
Four of the GC's we work for, mark up our work 100% or more. It is a real eye opener when the GC claimes he is hurting and needs your lowest price, then you find out later he charged the customer two or three times what you billed. Live and learn.
