Am I not correct in thinking we have a scottish builder that can build a bespoke rod already...?? Infact, two builders..David Norwich and Clan rods?
I think one of the biggest problems for such a scheme would be peoples attitude. For some reason people think that the best custom rods are made in the US (I think this is based on cost..its more expensive so it must be better). Place a Sage and a Harrison blank on the table and I bet 99.9% of folk would want the Sage. However, there are quite a few builders in the UK using Harrison blanks, Mick Bell being one of them, to build there own custom range, and people pick the rods up and say its the best rod they have ever used!
Using an American term...go figure
I really cannot think of very many custom builders that actually roll there own cloth..I have spoken with David Norwich at length about his process and the guy understands fishing rods as does Dr Harrison, although Harrisons are would famous for there carp blanks, very few have seen or used there fly rods.
At the end of the day I dont believe its the cost of the materials that would knock up the price, it would be the manufacture of the mandrels and the time and effort spent getting these right that would prohibit rods being made at a reasonable cost.
Lastly, manufacturers like Sage, Loomis, Daiwa etc have access to amazing facilities and materials that your average rod builder would never see. This means they can build lighter, faster, stronger rods than Joe Bloggs in his shed..but, it does not always mean they build better "fishing" rods