This cartoon from The Seattle Times illustrates how America's economic pizza is actually sliced per capita, highlighting the massive disparity between the Top 1%, the merely wealthy, the upper middle class, and the lower 50%.
Not buying the very last link in the chain doesn't matter.
It absolutely does. You're cutting out the part with highest markup. Skipping an entire manufacturing process.
You can get the ingredients for a fraction of the cost compared to a finished product.