What problem is that? How to spunk £200 Billion on something only rich cunts will be able to afford to use?
The problems are:
1) The current huge issue with capacity on the WCML. You can't solve this with more cars because there's no road capacity either.
2) Similar capacity issues on the local and regional West Midlands network (I don't know about the London end of things).
For instance, where I live they've wanted to reopen a train line for passengers for years (Camp Hill line for those who know) but the line runs into new street station.
They haven't been able to raise the money to build a connection to bring it into Moor Street but have been able to find a way to get one train an hour into new street and re open the stations.
HS2 will free up/create a load of slots in New street and might allow this line to have more trains per hour running. There are loads and loads of places like this in Birmingham that are bottlenecked by New Street station so I've no idea where might get what.
On routes which are not bottlenecked by New Street but will get more capacity from HS2, you can run more trains per hour because you have fewer trains running at different speeds.
Again, there's no road capacity to add more cars into.
3) The need to provide a form of transport that can replace short haul flights. HS2 to Birmingham only won't do anything much for this and really you'd want a direct connection to the continent but this would/could be a step towards a larger British high speed network which would.
As far as prices go, HS2 will replace the current high speed trains, allowing more local stopping trains in the existing network so we know what this service is. With the political need for HS2 to be a success, I don't expect to see ticket prices much higher (if any higher) than the current ones for Birmingham to Euston on Virgin or cross country or whoever currently has that franchise.
Perhaps first class walk ups will take a hike in price or something like that but standard advance fares? I don't see it.
For people who already use the fast train from New street or international it's a few minutes saved, for everyone else who previously had a direct connection, it's a longer journey. There is no extra value to HS2 from a West Midlands to London passenger point of view, the benefits to passengers will be felt in the local/regional journeys we make, which people won't connect to HS2.
The demand for the Bham to London journey exists, massively. The politics dictates HS2 needs to be a success. The market already has a price it will bear that brings success. They won't risk moving far from that price. These trains will be well used.