I see where you are getting confused. Share buy-back is not an...

I see your confusing expenditure (operating costs)

I see where you are getting confused. Share buy-back is not an operating expense. For example a salary of an employee is a yearly and ongoing cost. Money that has been banked from previous profit is now on a balance sheet. This is separate from a profit and loss statement.

So MFG using that cash reserve has no impact on how profitable that company is. If they spend it or do not spend it, does not impact the income produced or the cost of keeping the company running.

Hope this helps