It says 50x , but i am assuming even a 10x improvement in efficiency with the already crazy increases in speed would be great, hopefully with a way to recoup th

It says 50x , but i am assuming even a 10x improvement in efficiency with the already crazy increases in speed would be great, hopefully with a way to recoup the investment in 20-30 years. Also was wondering whether above ground system is cheaper outside cities than tunneling but i guess they feel that tunneling is cheaper if they get the purported 10x gains they want there