Open access (OA) refers to the free, immediate, online availability of research outputs such as journal articles or books, combined with the rights to use these outputs fully in the digital environment. OA content is open to all, with no access fees. It is a global movement that aims to improve the way in which researchers share their research outputs by making it easier for other people to discover, access and apply the findings of publicly-funded research.
The Directory of Open Access Journals is a website maintained by Lund University which lists free, full text, quality controlled scientific and scholarly journals, covering all subjects and many languages. There are over 8,000 titles in the directory, click here for the list.
The Directory of Open Access Books is a service of OAPEN Foundation (Open Access publishing in European Networks). The OAPEN Foundation is an international initiative dedicated to Open Access monograph publishing, based at the National Library in The Hague. The DOAB contains 1217 peer-reviewed books from 33 publishers.
Open access publishing makes it possible for more scholars, policy makers, practitioners, clinicians, and the general public to be able to view, cite, and share research. Library budgets are remaining the same, while serials costs are continually rising. Institutions are in the position of funding research, and then purchasing it back through journal subscriptions. Making research open enables access for people such as independent academics or researchers from less wealthy institutions, who cannot afford to pay for traditional forms of access to research such as journal subscriptions and expensive books. It is therefore particularly beneficial for people in developing countries.
The average cost of journals in may disciplines (especially in the areas of science, technology and medicine) is in the thousands.
Faced with high prices and sharp increases, libraries find themselves in a no-win situation. Researchers in every discipline and specialty need access to particular journals, and there is usually no option of finding a less expensive competitor. Many libraries' budgets for periodicals have been stretched thin, and eventually most will be forced to make substantial cuts in journal subscriptions or other library resources.
TLDR. Here is a list of average subscription costs of journals within scientific disciplines according to the 2021 Periodicals Price Survey.