It's a testament to the skill of publishers' FUD that we're still having this conversation. Authors don't get paid, reviewers don't get paid, product is disseminated via pdf, and there is still a "debate" outstanding such that a Fields Medal winner has to get involved to push things forward a bit.
A real estimate is available for JMLR, a reputed machine learning journal, about $10 per article (!): <a href="https://blogs.harvard.edu/pamphlet/2012/03/06/an-efficient-journal/" rel="nofollow">https://blogs.harvard.edu/pamphlet/2012/03/06/an-efficient-j...</a>
Here's two of Gowers' blog posts about Discrete Analysis, the journal:<p><a href="https://gowers.wordpress.com/2015/09/10/discrete-analysis-an-arxiv-overlay-journal/" rel="nofollow">https://gowers.wordpress.com/2015/09/10/discrete-analysis-an...</a><p><a href="https://gowers.wordpress.com/2016/03/01/discrete-analysis-launched/" rel="nofollow">https://gowers.wordpress.com/2016/03/01/discrete-analysis-la...</a>
>"Timothy Gowers's first big assault on academic publishing started almost by accident.<p>In 2012, the Cambridge mathematician took to his blog to write a post bemoaning the exorbitant prices that journals charge for access to research. Gowers vowed to stop sending his papers to any journal from the world's largest academic publisher, Elsevier.
tim gowers<p>To his surprise, the post went viral — and spurred a worldwide boycott of Elsevier, [...]"<p>>Be top scientist<p>>Publish a statement of intent on your widely followed blog<p>>People who have felt the same way but could not express their opinion without damaging their career follow<p>>be surprised<p>How much is this article insulting the reader's intelligence?