Related: chicken feet are also about $2/lb at my store, but yield many times more broth than a similar amount of meat or bones. It's also much tastier than canned broth, and you can make it very strong and store it compactly in the freezer for a long time. And you get to chase your roommate around with a terrifying scaly dinosaur foot whose claws open and close as you pull on the tendons.
Some butchers will give away soup bones for free as well.
Do you eat the feet after making the broth?
Thus spake Eliezer:
It seems that many here might have outlandish ideas for ways of improving our lives. For instance, a recent post advocated installing really bright lights as a way to boost alertness and productivity. We should not adopt such hacks into our dogma until we're pretty sure they work; however, one way of knowing whether a crazy idea works is to try implementing it, and you may have more ideas than you're planning to implement.
So: please post all such lifehack ideas! Even if you haven't tried them, even if they seem unlikely to work. Post them separately, unless some other way would be more appropriate. If you've tried some idea and it hasn't worked, it would be useful to post that too.