I wonder what are the actual costs of translating a manuscript of a textbook as given by the authors into a final publication (for web or print). I.e., ignoring the costs of marketing the book, and printing the textbook, and serving content via web.

I am mostly interested in the fields of computer science and maths, English-speaking venues, and the United States, but I am curious about other fields, languages, and countries as well. I am looking for referenced numbers, not guesses.