It is impossible to give 'dollars & cents' valuations, as the bike will sell for whatever any given person will pay for it.
But at the end of the day, this is a small wheeled, 'Klapprad' type U-framed folder, heavy for its size and not generally regarded as collectable. If you got it to enjoy or to upgrade it into something more practical, Great! If you got it because you thought it would be worth a fortune some day.............HoHum!