I don't buy the parent's arguments, but the $150m figure isn't too far from what Musk has pitched [1]: > Currently, tunnels are really expensive to dig, with s

I don't buy the parent's arguments, but the $150m figure isn't too far from what Musk has pitched [1]: > Currently, tunnels are really expensive to dig, with some projects costing as much as $1 billion per mile. In order to make a tunnel network feasible, tunneling costs must be reduced by a factor of more than 10. So, a factor of 10 is $100m, but we don't know what "or more" means at this point. [1] https://www.boringcompany.com/faq/ https://www.boringcompany.com/faq/