As I walked around, a gentleman helping at the church sale told me I had a moral obligation to buy stuff. Since "every penny helps people in need in our community." That settles it. I turned in the money and the 10 year-old receipts when I made my purchases. My conscience is clear.
Whoever despises his neighbor is a sinner, but blessed is he who is generous to the poor. Proverbs 14:21 ESV