The question isn't Mumbai vs Delhi. It is how costly is tunneling.
And I'm just pointing out that in India we are tunneling at around 10-15 million dollars per mile, far cheaper than what Elon musk thinks it costs (1 billion per mile), and what he plans to achieve (100 million dollars per mile). Essentially, the breakdown is complex and different for different geology, labor prices, tunnel sizes etc. Musk's salesmanship of selling byte sized numbers without context is stupid.
And I'm just pointing out that in India we are tunneling at around 10-15 million dollars per mile, far cheaper than what Elon musk thinks it costs (1 billion per mile), and what he plans to achieve (100 million dollars per mile). Essentially, the breakdown is complex and different for different geology, labor prices, tunnel sizes etc. Musk's salesmanship of selling byte sized numbers without context is stupid.