The cost of raw land may get exponentially more expensive, but the cost of higher density building is at most marginally higher than low density building. For

The cost of raw land may get exponentially more expensive, but the cost of higher density building is at most marginally higher than low density building. For example 50 story skyscrapers are actually slightly cheaper per square foot than 10 story buildings on a per square foot basis. Without artificial restrictions on density, the cost of housing is essentially invariant to the cost of raw land.