It already costs more than that.
https://www.thestar.com/news/city_h...-already-gone-over-its-available-funding.html
"A new report released by city staff Tuesday said the one-stop extension of the Bloor-Danforth subway to the Scarborough Town Centre is now estimated to cost $3.35 billion.
But that figure does not include nearly $600 million in additional costs that are detailed in the report but left out of that total."
In reality, we're already at nearly $4 billion - this doesn't include the cost of financing and other costs not detailed.
There's a reason they don't want to update anyone before the next municipal election - everyone can campaign on the issue, and then whomever wins can backtrack early in their mandate as the cost goes beyond the already-unjustifiable number they're at now.
So from a productivity standpoint, it will take about 60 years for this extension to be worth it...that's assuming the price doesn't go up from the nearly $4 billion it's at now (which it likely will). Meanwhile we have a project like the DRL, which should've been built decades ago, likely causing a far greater loss in productivity
right now. If you're talking about transit that benefits productivity, then there are a lot of projects that make much more sense than the SSE.
As you pointed out, none of this would matter if one took the Crosstown. Since we know that 77% of all transit trips originating in Scarborough
aren't going downtown, why not invest that money in a terrific LRT network which will serve the residents of Scarborough
and provide a transfer free connection to the Yonge Line?