Most folk that travelled on Concorde were businessmen/women, so most times the fare was 'expenses', and tax deductible. I did it once, for which the Company paid, and it was very expensive. Just to get there a bit earlier? Not worth it really, but a great experience, and the service from departure to arrival, was first class. although the headroom, as you rightly say Paul, was limited, especially at 6' 2"!
The proposed HR2 London/Birmingham route, will, I suspect, also be a 'business special' with high price travel. Will the majority of rail travellers use it? Only time will tell.
Now that New Street Station has had a huge financial 'makeover', with lots of great photos and comments, perhaps we ought to start an HS2 thread. Get some members views on a subject that will greatly affect Birmingham.
Eddie