Dear Fedora
Many thanks for your reply. I understand what you are saying about the difference between the "estimate" and a "quote", but do feel that the amounts displayed are misleading. It is not as if the increase is just a couple of pounds, but in my case, was in excess of a hundred!! A hundred pounds is a lot of money to me.
People use sites like these to make life easier and to have the ability to compare like for like products. I feel that this comparison is not fair as the goalposts change when you change screen - I do not know if some of the seemingly more expensive "estimates" quoted changed to the same degree.
I purchased my insurance directly from another site, and will continue to do so and advise friends/family to do the same.
I did however, use the site for broadband and got a very good deal (this remained the same price no matter where I went).