Method to determine Cost per visitor/revenue via Content-Marketing

[hpvd]

Would be awesome if there would be a method to work also "internally" with aom's great feature set.

In Details:
Lot's of websites have a blog or a Wiki or ... to attract people via good organic search results (Content-Marketing)
Of course building these content costs some money too.
Typical values for doing that in high quality would be about xxx-xxxx€ per page/article (including planing, research, text, images etc.)
Is there a way/method to use AOM to determine if it's a good or even better way than paying for google/bing ads?