I have had similar. After the first one I try to be prepared for it. When they get upset a lot depends on how belligerent they are.. If they are BAD I just leave, if they arent too bad I explain the cost, I show them the newspaper clipping I carry of a repair bill of over $7000.00 to a house the owner used a bug bomb in his attic to kill bees and I leave my card.
Usually after getting a few more prices those I gave my card will call me back.