Generally when i get a call simply explaining how prices are based is good enough. But occasionally like today they insist that i come out and do a "free estimate "in these cases the estimate is free only in the sense that if they by chance go with someone else they owe me nothing. But if im hired ill make eighter .05 or .10 per sqft more than if i just booked the job over the phone. The estimate is free but the price is more because of the second trip