Update September 28: kudos to the Max Planck Society (MPS) for a really ingenious approach! The MPS will pay the publication charges if the first author is affiliated with MPS; however, they will ONLY pay the amount for an article formatted properly according to the technical specifications. If the author chooses to submit an article that will cost more because more work is needed, they can do so, and pay the difference.
The open access journal Hydrology and Earth Systems Science uses an approach they call service charges which may be of interest to publishers looking for ways to transition to open access.
Service charges vary by the number of pages (not unlike the traditional page charges), but also by the format the author uses to submit articles. In other words, an author can keep the fee down by submitting in Latex rather than Word, and/or by submitting according to the technical specifications for either Latex or Word. A 10-page article submitted in Latex according to the technical specification is €450 + 19% VAT, $657 US before taxes, $800 US total with taxes. Not bad!
Authors can choose to pay for copyediting, or take responsibility for this themselves.
The service charges approach seems to have some merits. At the very least, it is helpful, in my opinion, to think about publishing as a service.
This post belongs to the series Resources & Tips for Publishers.