You are making an assumption that all pageviews are of the same relative value, they are not. The value of a pageview varies a great deal based on your targeted audience.
You are also assuming that all industry niches have the same relative value, they do not. Advertisers are not willing to pay the same for every niche, in fact, most advertisers adjust their bids on a site-by-site basis, and in some cases on a page-by-page basis.
To get anywhere close to an estimate you need to nail down as many variables as possible, otherwise, any number you come up with is just a wild guess. Even with all those variables in place, it is still very imprecise because of the enormous number of variables.
This forum has many types of members, but the real marketers among us do not try to make such theoretical estimates. Real marketers set up tests, gather data and make data-driven decisions. Trying to use aggregate data is nearly worthless, using aggregate data from unrelated websites is completely useless. You can look at aggregate data from other websites, but it has little or nothing to do with what you might expect on your own website.
