I have found realtors to be a fantastic source of wasting my time. They use roofers for free inspections. If they represent the buyer, they want a HIGH quote to use as a negotiating tool. If they represent the seller they want a low estimate to use as a negotiating tool. If the house is for sale figure 6 roofers look at it. 3 for the buyer and 3 for the seller... and in most cases none of those 6 roofers get the job because the roof usually has a 3-5 years left and the buyer waits until it springs a leak... or the buyer has a temporary fix done instead of a repalcement.
I speak on this subject from experience. I have made it my policy to charge for all estimates if the house is involved in a transaction... I will make exceptions in special cases.