>>4177337Proves my point even more. Which sensor was more expensive to produce, the one in the D5 or D850? By how much? There is an overall price difference due to development, yes, but it's mostly markup.
The price difference between an 800MHz memory chip and 1600MHz is pennies at the end of the day. In many cases it's nothing because they are the same chips, just binned. Same goes for most silicon including CPUs and GPUs. Are faster chips lower yield so more valuable? Yes. But not by a factor anywhere near what you're paying as the end user, especially once R&D costs have been covered. Pro cameras are just a lot of cheap parts with expensive sensor development, much of which is software, some of it licensed. That development isn't much more expensive than an entry level body though. The difference being, Nikon will make entire lines with those cheaper ones. They made 12 from the D3000 and D5000 over 10 years with the same 5 sensors used in other models including D40 with minor revisions at most.
Even the much touted magnesium bodies of pro cameras are cheap to produce and in many cases cheaper than plastic and easier to assemble, especially with automated tooling. The moulds often last a lot longer because you need less complexity with metal (less reinforcing ribs, gussets, etc). Plastic extrusion is hard on moulds. A die-cast toy car at the dollar store was made the same way as a D5 body.
Hardware and software wise, you are looking at a very small difference between a D3200 and D5 and that wouldn't be a factor once production began. Parts-bin wise, they are much closer than people may think since while one component may be 4x the price of another, we're talking $1 vs $4. Shutter mechanisms? Pennies worth of difference in materials and using the same production methods. Sensors? Only because production runs are lower.
It's artificial and self-imposed to create and protect markets. Everything is always marketing and has to be; look at how well it works.