Once upon a time, you treasured your Jetsons lunch box. Now it sits on a shelf in your mother's basement. Someone out there would like to make it feel loved once again—and possibly pay you thousands for the privilege. In general, you know you've got a valuable piece if it features a cult TV show (Star Trek is hugely popular) or a comic book hero like Superman. The 18th edition of Toys & Prices, a guide which lists values for collectibles, says plastic lunch boxes currently sell for between $30 for common models and $150 for harder-to-find items like a 1964 Popeye, Truant Officer lunch box by King Seeley. Steel lunch boxes are more prized than plastic and go for between $65 for everyday models and $5,500 for a rare 1978 240 Robert by Aladdin. As for that box in which little you carted PB&Js and carrot sticks, the 1963 Jetsons Dome by Aladdin is currently valued at $2,650 (plus $375 for the thermos bottle if you've still got it).