There's a very good chance that a small fortune is gathering dust in someone's kitchen cabinet right now. Grandma's old casserole dish, that funky mixing bowl from the thrift store, the colorful glass ...

A woman shopping in the kitchenware section of the thrift store - Hannah Bernabe/ To the uninitiated, Pyrex pieces might seem like items of little value. Functional, sure, and nostalgic for many, but ...