I have seen questions like How much does a square inch of ink cost and How much more will a high-dpi image cost to print?, but mine isn't asking neither about a specific case, nor about how much something costs, as that would depend on the toner, for example.

Rather, I was wondering how should I go about calculating the cost of printing a given page. Note that "given page" should be seen as a sort of x, i.e. the answer should be applicable in any case; I'd like this question to provide a good reference for those who want to calculate this cost.

What should be taken into consideration?

The cost of a single page (the paper only) is easily checkable, since you divide the cost of the whole package for the number of pages in the package itself. But how do I calculate the cost of the ink/toner? Which could translate to: how do I calculate the Ink Density¹ for a given printer?

I know it depends on quality of the printer itself, the type, the quality of the image being printed, the very nature of what I'm going to print, etc. But again, the focus of my question is not on the variables of this case, but rather the constants, hoping the math simile works for this case too.

^{1: Total amount of ink in one area of the page.}