If you've ever spotted those colorful, nesting Pyrex mixing bowls at a yard sale or tucked away in your grandma's kitchen, you might wonder if they're worth more than just a pretty vintage find. The ...

There was a time when no respectable casserole or Jell-O salad was served in anything but a brightly colored piece of Pyrex glassware — and every cupboard was stacked high with the functional mixing ...