Those numbers surprise me. I know it is a lot of money but honestly I would have expected underground infrastructure like that to cost a lot more. Maybe it is a regional thing.

Small tunnels and no stations, plus I would presume good ground for tunneling. All together, a smart way to take advantage of tunnels’ strengths while minimizing their weaknesses.

Probably because we know how. After the Gotthard I am sure there are still machines and very skilled people working for their next big gig.