Is there an affordable way for non-students to subscribe to multi-journals/archives?
Many papers are freely available on authors' websites, and preprint servers (use search engine to find those). 
Write to the authors, asking for copies. Majority of academics are happy when their work is read, and will send you a copy.
Your public library might subscribe to more than you suspect. Check it out. When I was a student in a community college, my local public library subscribed to JSTOR for example.
Become a student or an academic again :-)