This is where your thinking is wrong. First the only way to get a real price is to talk to people that may actually do the work.But I'd hate to call people out for estimates before we are really committed to having it done.
Second, the work that the contractor is doing today he likely had scheduled months ago. The job he's doing today is maybe for someone that first contacted him a year ago (or more).
This time of year when the phone rings I'm praying that they don't want it done until fall or later.
You can't start the planning processes to early and how can you plan anything without real numbers to work with?