[jcranmer]

A parking space takes up about 200 ft² (not counting things like the width of the travel lane between parking spaces), and office rent in Manhattan runs about $7-8/ft² each month.

Chances are, even at well over $1000/month, the parking infrastructure is still effectively below the cost of the space it takes up.

[NovemberWhiskey]

On the other hand, a parking space is a bare concrete slab, or even a lift holding several cars over a bare concrete slab; and an office building is ... not.

[tmnvix]

As I understand it, parking buildings are actually more expensive to construct due to the engineering requirements