[avemuri]

I'm not sure about the cost. A lot of Mumbai's middle class housing is 30-40 floor towers. These are flats that sell for well under 200k, most under 100k. Labor cost is lower in India, but most material and equipment costs are not.

[OkayPhysicist]

Another cost difference that you're not accounting for is building code. It would be entirely unacceptable for an SF skyscraper to fall down in a 7.9 magnitude earthquake. Likewise, fire safety is a huge factor in the US, and especially in California. Safe evacuation routes for people get more and more difficult to provide when the number of stories climbs higher, too.