Back when Lotus were trying to sell their active suspension technology to General Motors (who owned Lotus at the time iirc) in the '80s they were told that the 4 springs cost them $1 from their supplier and the dampers were $1 each. The Lotus used 4 Moog servovalves which were $1000 each. They would have got cheaper if tooled for mass production but at that stage they accepted it was going to only be on more expensive cars (and still hasn't made it to market).We would probably just end up boycotting most products if we really knew what they cost to make compared to what we pay.
Decades ago I worked at a Ford dealership; Ford would have a fair amount of parts shipped directly to us from their manufactures. One day one of the parts had an invoice attached that was the bill to Ford for the part. It was a small metal bracket that Ford charged us around $25 for. We would then sell that part to a body shop for around $32. The body shop would charge their customer $48.
The price that Ford paid? $2
On the subject of audio I was told when I worked for Garrard that with the exception of the platter of a 401 which was machined on a gear cutting machine, the most expensive component to make was the instruction manual...