all i'm basically saying is that contractors are very similar to car salesmen
they prey on joe homeowner not being comfortable or familiar with the details so that they can maximize their profit
which is fine, as long as it is done in an ethical manner (which many car salesmen and contractors might not follow!)
the mis-information and the predatory nature is what bothers me, the unethical (IMHO) nature of it
Just had a furnace installed, the contractor steered me away from duct cleaning and vari speed blower motors as they considered them a waste of money - the crew hustled hard, and my cost was a value