12 USD is the current cost per submission. But I do not think that they need to 2x their budget to handle 2x the amount of articles. Marginal costs per article

12 USD is the current cost per submission. But I do not think that they need to 2x their budget to handle 2x the amount of articles. Marginal costs per article will be lower. But your point stands, this stuff costs real money. So I just donated 100 USD to Arxiv, as they host a few of my papers. And thousands of other articles that I have read, for free and super accessibly.