Keep in mind:
* This is in 1950s dollars. Adjusting for inflation, that's significantly more expensive in today's money.
* Luxury cars cost much more. A Cadillac or a high-end Chrysler would have been at the higher end of that range or even beyond.
* Basic models were cheaper. Smaller, less-featured cars were available at the lower end of that price range.
To get a better sense of the relative cost, consider that the average annual income in the 1950s was considerably lower than today. Buying a car represented a substantial investment.