If you want to own a 1957 Chevy, there are two ways to approach it. You can buy an old rusty shell , and start a rebuilding project, that could take years. If you go this route, it can take a long time to finish, and can require thousands of dollars in parts and supplies, and labor. Once finished though, a fully restored 57 Chevy can sell for tens of thousands of dollars.
The other way to own a 1957 Chevy, is to just pay for one that has been restored already. In order to do this, you need to be prepared to pay 10s of thousands of dollars. Some even approach and exceed $100.000.00.