Convinced by what exactly? Your closing sentence has no connection with your opening one - has your post gone through an edit too far, perhaps?
I'm not sure why you're surprised by the cost of Cobbett as I thought you'd visited Dave and Ian to discuss a possible build with them so I would've thought you would've had a very close idea. Cobbett came in just under budget on Dave's projections and was considerably less than the price that SMH suggested as a ballpark figure by over 25% for the same spec boat. I knew that the delivery time was likely to be in excess of four years (finished and handed over within three years in fact) but I also knew what I wanted and was happy to commit to the queue. At no time could I persuade Dave to take a deposit and if I had changed my mind I was under no obligation to build. In fact, one of the reasons she was reasonably cheap was because Dave noticed that some Hartlepool steel was available with a caveat that prices would be rising by 9% next month and rang me to find out if I wished to buy it as he was happy to store it until he or anybody else started to build Cobbett. I'm not convinced that that would happen in a big yard - perhaps there'd be discount but I'm not sure you'd get an invoice with the price the builder paid, clipped to the back of the account which matched to the last penny.
I suspect that some of our finest builders are single builders probably because they prefer it that way and because they know they are able to control the build of the boat and maintain an exceptionally high quality standard. In my experience, they tend to be quite singular characters too, the encyclopaedic knowledge base extended to waterways and railways of Europe and morris dancing, all of which I love (go me!). Because Dave works by himself and because I wanted to work on the fitout he gave me the very best of his experience and time, I learnt how a boat is built and the reasons behind it. Dave works to a very strict timetable which is a transparent process and so if it was say build day 142, Dave would be fitting the plummer blocks and propshaft and I would be painting doors 3,4, 5 and 6 and putting in the Gulpers. I do know the old adage that the final act in building a boat is that you fall out with your builder and I am happy that that didn't happen; we did have one major problem in the build but Dave's response went far beyond what I might have reasonably expected. I must also confess to ending up in tears when he told me that my tiling skills were not up to standard and they had to be removed, the firepanels replaced and I had to start again after a lesson on how to do it to Harris standards. I am still on excellent terms with Dave, Andy Downing and John Sanderson who all worked on Cobbett and gave me their knowledge without hesitation or demand and for whom I have the highest regard.
I now have a boat I love, a number of very good friends and have learnt more about boats and life on the cut than I ever realised I needed to know. That, for me, has value beyond money.