Originally, work estimate was only for the house water valve, shower drain, to switch hot and cold water to second shower and yo hook up the utility sink in the garage. At the time of the estimate, the representative fixed the 'hot and cold problem' with the second shower by making adjustments to the Moen valve with no charge (a previous estimator said that the fix would require cutting and switching the feed pipes under the house) When work started on replacing the shower drain, the technician was unable to hook into the original sewer line as the pipe apparently crumpled when he tried to work on it. The estimator then took photos of many of the joints in the original sewer system which all appeared to have thin white lines (calcium deposits) coming from them suggesting many slow leaks from inadequately glued joints. He told me that this was a result of using some sub-standard pipe which had commonly been sold in the 1970's where the manufacturer had produced out-of-spec pipe that was then melted down and re-cast. The result was that the reformed pipe late proved to not take glue well in the joints, and ,with time, became very brittle. I was advised that retaining the original sewer lines would risk an eventual breakage of one of the lines which would probably not be detected till after the under house crawl space was flooded with sewage. At that point, there would be a significant clean-up cost incurred as the need to replace the sewage pipes. I therefore opted to have the company go ahead with their recommendations and replace all the sewage pipes in addition to the original work. I could be wrong, but the final price did seem a little high. However, I was impressed with the original free fix of the hot/cold water shower problem and It was not practical to get further estimates, so I accepted their final estimate.