> Assume that the value of these altcoins do not change, and see how many you can mine given a certain amount of time. The value of altcoins could very well go down, but for the sake of demonstration you could still calculate a very rough estimate, no?

And likewise if you assume values for the cost of apple seeds land, see how many apples you can grow given a certain amount of time - and the value of apples could very well go down - but for the sake of demonstration you can also calculate a very rough estimate of apple orchard profitability, no?