[jcranmer]

I'm not sure how many articles are published a year in ACM [1], but the answer seems to be a few 10,000s. That's a per-article publishing cost of a few hundred dollars, which is not unrealistic to me.

[1] The ACM Digital Library claims 2.8 million published over 84 years, or about 33,000/year if divided equally over the years (which is laughably false). Some number of that quantity may include citations for keynotes or posters, which aren't really research papers, but I don't have a good handle on that rate.

[julierthanjulie]

Annual report 2019 gives some details - 34,000 full text articles were published in the DL. This will exclude non-archival content like keynotes, posters, etc if conference organisers provide correct metadata.