What's been your best yard sale buy ever?

My best yard sale find was a string of pearls that a young college girl sold me for five dollars. They matched the slightly gold/ivory pearl in my favorite ring. I discovered they were real and took them back to the young lady, but she didn't want them back. She told me that they were given to her by her grandmother and she thought they looked too old fashioned. I gave her my card and told her to feel free to call me if she changed her mind, but she never did. I never had them valued. I am sure I could never enjoy wearing them if I knew what they were really worth.