Depreciation is in the game. Add it to the corporate balance sheet -Aries

By design, production process quality and effectivity upgrades decay over time. While investing in them could be considered a post-profit transaction, their decay should be considered an expense, and reflected as a pre-tax expense. This transparency would be a helpful tool for players to track the true profitability of their corporation, their enterprise, and their countries.

I will look into it.
the problem is, that "cost" is subtracted from the cash, or otherwise the math will be broken.

here, the cash is reduced when you purchase a new one.
then cash is reduced.
I am not sure if the cost is increase by the amount used to purchase them.