>First of all, the reviewers and editors of journals often work as volunteers -- so the notion of cost here is somewhat dubious.
The reviewers and Editors (in the editorial sense of the word) are not the largest contributors to the costs associated with publishing an academic paper -- that's why they can be done for free (in the cases they are). When they are done for free they offer some other career-enhancing benefit.
Most of the cost relates to making the sausage, if you will. The manuscripts must be wrestled into a form that can be printed. That is boring and tedious work that you have to pay someone to do. There's the cost of the infrastructure required for these folks to do their work. Then there's the continuing cost of hosting the digital version(s) of the article.
I believe preparing an article for publication and distribution can be reduced to a fixed cost -- provided all parties involved cooperate.
It would be helpful to think about _why_ academic publishers exist in the first place before tossing them aside. Otherwise we'll just end up with the same situation we have now.