Can a scholarly book be (semi-)self-published, peer-reviewed, available near cost in print editions and free in pdf? Yes.
Comparative Oriental Manuscript Studies: An Introduction
Granted, this is a technical academic handbook for a narrow academic field and specially funded. But a similar model could surely work for the monograph. I would add: such a model should include a standardisation of typesetting for print versions and book-like electronic versions (like pdfs). This particular volume is a strain on the eyes for all the text that fills each page (in the pdf version, at least).
I suppose PhD theses in the humanities, increasingly subject to open access requirements, are similar: Peer reviewed scholarly works of monograph length available via in electronic form for free. Of course, there is this business of “getting published” (in the traditional sense) that, in my field at least, is an important step for advancing in one’s career. There are other obstacles, to be sure, but I am intrigued by the idea.
(On the release of this particular volume, HT Brice Jones)