The 222k are the really expensive ones. With that said, there are some rare 221 US World Fair badged ones that can be even more. They are worth what people will pay for them. Demand will change depending on where you can sell it. That's why Ebay is a great place to sell them, you can open up your product to so many people. Some have chrome scroll faceplates, and chrome edged fly wheels, some have graduated feed dog covers. All these add up for more value. They are fun to research and learn about. Your lucky to have one. If your going to use it, even better.