To partly answer your question, Pubmed central hosts a large fraction of all biomedical research papers relevant for only a few US$ million per year.

https://pmc.ncbi.nlm.nih.gov/about/faq/

BioRxiv is free to researchers and is equally low cost.

https://www.biorxiv.org/about/FAQ

The value prestigious journals provide is not so much in the editing, type setting, or hosting services, but rather in the ability to secure properly-conducted scientific reviews, and to be trusted to do so.