There are some common grocery items where the price doesn't phase me at all. Yogurt? No problem. Sugar? Got tons.
But for some reason, I find chicken broth absurdly expensive. Or filled with chemicals. Or both. When I'm making a recipe that calls for something like 7 cups of chicken broth, I am filled with horror.
You can make your own chicken stock by boiling chicken bones, but I rarely, if ever, buy chicken with bones in it, so this doesn't really solve my problem.
I do, however, buy a lot of vegetables and there are always parts of vegetables you don't really eat on their own (the tops of celery stalks, carrot peelings or tops, the ends of onions, broccoli stems, etc). And frankly, I don't really notice a difference between chicken broth and vegetable broth.
Over the course of a week or so, I put the leftover vegetables parts in a tupperware until I have a good little pile.
I toss it all in my stockpot, cover it with water, put in some bay leaves, garlic, salt and pepper, and let it simmer for a few hours. Then I cool it, strain out the vegetables, pour the broth in my ice cube molds, and put the frozen cubes in a big tupperware in the freezer.
Then, when I need it for a recipe, it costs me virtually nothing, even if the recipe requires a ludicrous amount of broth. Plus, I get to feel good about not having wasted my vegetables. Not to mention that it's not filled with weird ingredients.