lens design – Where can I find the production costs of lenses?

I am very curious about the distribution of lens production costs. This information is difficult to find and I am unable to find reliable sources. Obviously, I can not simply send an email to Canon to send me their financial statements, but I hoped that someone here having worked in the field of design / engineering would like to send me an email. objectives could provide a rough estimate based on their experience. Just to take a classic design, maybe a 50mm f / 1.8 lens or a 70-200 2.8 lens (all brands).

I was thinking of a breakdown like this:

  • Raw materials
  • Polishing / treatment / coating / etc.
  • Assembly
  • Packaging
  • R & D
  • Marketing