This question comes up in every one of these threads and this is the correct response.
If you look at the line items on a build, you might see something like a $200 bolt. It’s not that there was $198 of R&D going into the design of the bolt, it’s that quality management drives the cost. Chain-of-custody, bonding, material testing, witnessing etc. are all part of that effort and they don’t scale like a design spec does.
The GPs point was that subsequent builds would make it no longer a one-off design. My point is that there are other substantial cost drivers that break their assumptions. My analogy of a $200 bolt was not meant for a custom design, but the point stands regardless.
(I’ve worked in a custom machine shop for aerospace, and depending on the tolerances, the actual build is typically not thousands until you factor in all the aspects in my previous post)
If you look at the line items on a build, you might see something like a $200 bolt. It’s not that there was $198 of R&D going into the design of the bolt, it’s that quality management drives the cost. Chain-of-custody, bonding, material testing, witnessing etc. are all part of that effort and they don’t scale like a design spec does.