There's a table in the PDF on pages 55-56 that shows the tube & pylon cost breakdown. In the small version the tube costs $650mm to make. In the large version

There's a table in the PDF on pages 55-56 that shows the tube & pylon cost breakdown. In the small version the tube costs $650mm to make. In the large version, which has 60% more material, it's quoted to cost $1200mm to make. That's an 84% increase in cost for a 60% increase in materials. The other costs in the system such as the cost of pylons, installation, etc are individual line items on the overall budget of $5bn or $7.5bn