question: mountain town zine collection

I live in a tiny town in the mountains. We are a town of readers and thinkers, and have our own very small collection in a volunteer library. We're proud to say we keep no records for the FBI to peruse. We'd like to add as many zines and other materials "beyond what is reviewed in Library Journal" as we can. Unfortunately, we have no budget and depend upon donations. Do you have suggestions for finding back issues of zines or other material at low cost? Can you suggest a short list of zines we should save our pennies to purchase?