Then how do they cover the cost of R&D, marketing, and payroll, if not from the cost of their products they sell ?
Where do you think the money comes from to pay operating expenses?
It seems you misinterpreted what i said, i did not say operating expenses are not included in the product consumers buy, i said "You can't, or at least shouldn't, include R&D in a products cost". As in what it costs to produce said product.
Operating expenses are paid for out of your overall revenue, they come from adding X% to what it cost you to make the product.
That's an extremely simplistic view to not include operating costs. They simply have to be a factor as it's not only the material cost in making a product that dictates it's price.
Granted the prices of GPU's could be cheaper but they are a business so it's upto them how much they price it based on supply and demand.
It's not my view, it's the generally accepted view of accountants. The only thing that dictates the price is the cost in making the product, operating expenses are added onto that cost after you factor in what it cost you to make said product.
If it costs you £100 to make something you don't say it's cost you £150 because operating expenses, you say it cost you £100 to make something and you need to sell that to customers for £100 + X% to cover operating expenses.