Land acquisition cost matters a lot actually. Despite all the advanced features required for high speed travel, the Mumbai-Ahmedabad HST corridor is still cheaper than the Delhi Metro 3rd phase, which has a projected cost of 221 crore per km for overhead lines and a whopping 550 crore/km for the underground lines! Constructing a single, dedicated passenger transport system like the hyperloop, in an uninhabited desert, and in parts of a well organized city, will cost far lesser.