Eddie Murray Card
Back in 1993, I got this card in a pack. It was worth $75 when I got it. I thought for sure this card would be my retirement fund. I should have sold the card the moment I got it.
As the years went on, Eddie's taciturn face was a rebuke for my idiocy. I eventually gave the card to a family friend who'd started collecting.
Today, it's worth around $18. Ah, the folly of youth.