So, moving away from stockpiling, now I wait until my favorite shoe goes on clearance at the local running store and just buy one extra pair. They still make a profit (their markdowns are not gigantic), and I feel good about both saving some money and supporting them a little. It's easy for me to find my shoe on sale, because I wear a weird size that never sells.
I can't make myself buy any running clothes or shoes for full price, even to support a local business, so this is my compromise.