Comment by Yetanfou

One of the solutions to the €journal-implosion problem is to publish in both €journal as well as the new, open access version and to make this known in the article. Make this an institutional requirement for publishing in €journal in the first place and require Elsevier/Springer/Wiley/... to include the reference to the free version (no reference means no publication in €journal). The versions published in €journal might be better edited (or it might not, depending on the journal) but the science published is identical. Do this for a few years and the open access version will have built up enough of a corpus and a reputation to become a feasible replacement for €journal. Now you can either drop €journal cold-turkey style or start off by having the established names publish exclusively in the open access version while the up-and-coming still have the choice of publishing in both. Once it becomes known that the most revered names exclusively publish in the open access version it'll be game over for €journal. Once this becomes the norm in enough fields it'll be deemed irresponsible to publish through the likes of Elsevier and the world will be a better place.