Parking spaces don't 'cost' anything. The apartment building already owns the land. Anything after that is just a discussion on what the best use of it is. But they're not paying more for where they allow cars to park. And they're not paying less for where they allow people to live.

If the argument is that the space required to park a car is annually as valuable as the car itself then that just seems to promote the idea that we should be using those spaces for housing and not for cars.