You could buy 2 candy bars and have enough left over to buy two Tootsie-rolls or 2 Bazooka Joes with 12 cents.
Perhaps they were just taken for free off the hands of some mom who was sick of her son reading “those comic books.” An alternative to throwing them into the garbage—which was the common final resting place for most comics.
When we first discovered this trick, we of course bought every single old Marvel around. There were maybe three or four merchants in the neighborhood who sold used comics. They kept them in boxes behind the counter, so you had to ask for them. These were places that did a brisk trade in 15-cent egg-creams and nickel bags of Wise potato chips.
We were relentless in pursuit of the older issues. We researched leads. We traded with each other. My goal in life was to get every single Fantastic Four and Thor. We wanted them all.