I think the name 'Bull' is apt.

we have had similar people assessing the condition of the walls of our house. They gave us a quote in the thousands. I laughed at him. I could have done it myself with a latter, a few hours and about £50 for what they were offering.

Most, if not all door to door salesmen are like this. Most, if not all double glazing sales teams, people who sell kitchens, anyone selling stuff who says 'we don't advertise and therefore they pass the savings onto their customers' are all "Bull' marketers. I have a particular hatred for double glazing salespeople (they, incredibly, call them 'designers' these days which is a joke). Some are incredibly agressive and offer the old 'we will only give this discount now, tonight' or 'if we can put a sign up to advertise because you are near a phonebox, we will give you another discount, but only if you take this expensive, complicated finance scheme'. It's all nonsense, it's all a con, don't fall for it.