To me, $1000 per article sounds insanely low. PLoS is a non-profit founded for the purpose of publishing open-access journals. They charge between $1350 and $2900, depending on the journal, and only one journal is less than $2200. Another open-access publisher, BMC charges over $1900 for most of its journals. Do you think that PLoS and BMC are very inefficient? Are there _any_ large-scale open-access publishers that charge less than $1000? I don't count low-volume journals where the administration work is done by professors on donated time that would be valued at more than the cost of hiring a professional.
Sources:
http://www.plos.org/wp-content/uploads/2014/09/about-journal... http://www.biomedcentral.com/about/apcfaq/howmuch