From my experience, libraries are usually the cheapest. Most charge around $1 per page for local faxes. Post offices are a bit more expensive — around $2–$3 per page — and UPS can be the priciest, especially if it’s an international fax. I found a very helpful comparison on
mattallenartistry.com
that breaks down prices for all these places and also looks at mobile fax apps. What’s great about apps is that they’re much cheaper — sometimes just a few cents per page — and you can fax directly from your phone without leaving home. I switched to using an app after seeing the comparison, and it saved me both time and money. Now I don’t have to worry about store hours or paying high per-page fees.