awinkler wrote:nvmos2: What's the silent salesman?
In 1987, Bill Enes wrote a great reference book he called "an encyclopedia of collectible gum, candy & nut machines" entitled Silent Salesman.
In 1995, he updated it and published Silent Salesman Too, a greatly expanded version that also included other type vending machines, both books had a separate price guide available as well.
If you collect coin-op, it should be part of your library.