I am interested to know the cost of publishing an academic article. I do not mean in the simple sense of "what does a given journal charge an author to publish?" or "what does an association or publisher charge a library for access to the journal?"
Instead, I want to know the actual costs of translating a manuscript into a final publication (for web or print). This matters for open science - and open access specifically - because there is an enormous amount of debate about the financing models for open access journals. The two dominant models are one where the end-user pays (library, reader, etc.), which is often seen as antithetical to open science, and one where the author pays a fee after manuscript acceptance. Neither the charges paid by libraries nor the charges paid by authors necessarily illustrate the true cost of publishing an article (due to "prestige", between-publisher variation, profit margins, journal bundling, discounts, etc.).
So, what is the actual cost? And what are components of that cost (e.g., copyediting, typesetting, server space and internet bandwidth, etc.)? In short, if an author (or someone else) were to express academic publishing costs on a per-article basis, what would that number be?