"Currently, all the costs fall on HS2, whereas the profits from the oversite development go to the Treasury. So although both are effectively arms of the government, the Treausry’s desire for a larger oversite development piled costs onto HS2 that it is not able to offset from the extra property sales."

Remarkable how rules accounting rules like this can derail a project. Clearly any foundational costs for commercial development should be billed out of the profits coming from said developments.

It's beaurocratic bullshit like this that results in short term thinking with any attempt to build a better more profitable staion being expressed as a project overun and resulting in cancellations or scale backs of critical features.