The Guardian tells us HS2 costs are under review by Sir Jeremy Heywood. I think the design should be scrutinised too.
By Cnbrb (Own work) [CC0], via Wikimedia Commons
Commentators point out that most along the route feel disenfranchised, just bypassed. That need not be the case. Most motorways go past city centres, but connect to local routes. Why not do the same for high speed rail?
Building new surface stations in already crowded and busy cities is a huge proportion of the cost, and of timescale. Why not take a leaf out of Crossrail?
In short, don't just look at the money. Reconsider the design.