Are those just estimated capital expenses or do they bizarrely include 30 years of operational expenses like the OL ? Make it make sense.
The current running capital estimate at an early design stage is 4.94B.
However, that's if the project started tomorrow, more or less, which it won't.
Its also with no tunnelling other than exiting Kennedy Station.
The overall length (including Malvern) is ~18.6km (most of the route is known and fixed, but there are still some up in the air bits).
Current cost per km for the Eglinton Crosstown West Extension which would likely be a good comparitor with partial tunnel/full separation is 4.7B over 9km. Or over 500m per km.
But my understanding is that it running over budget (TBD)
That's for a line under construction now, with no forward inflation.
The streetscaping components also likely more an issue here based on prelininary design, plus a complex interchange at Kennedy........and a SMF that is not yet a settled issue either, nor is its interchange with Line 4.
I might be a bit excessive in my estimate.......the exact numbers would depend on contract and finance model. But after everything that's gone wrong with Finch and Hurontario and the Crosstown, I'd expect a bump not a decline.
Just to add one last comparitor, the WELRT, mostly on the surfact is estimated at 3B with a 3.8km running distance...which is 750M per km. That price per km would get you 14B for a budget.