That’s why flea markets are awesome!

A London woman, who bought a piece of costume jewelry at a flea market 30 years ago for $15, is now expected to sell it for $454,000 at an upcoming auction. The woman thought the 27-carat diamond was fake. It turns out it is real.
She would wear it out shopping, wear it day-to-day. No one had any idea it had any value at all.