The cost per coach is very high as this is the initial rake that is being leased. A technology transfer, if successful, will bring down the costs greatly.
Ideally, the fare for Talgo should be similar to normal fare as IR would be saving a considerable amount of money in the maintenance and more importantly, the running costs of the rake ( With a projected 30% energy savings over conventional/LHB rakes ). The most ideal option is to use Talgo for Shatabdi trains instead of adding a separate class of trains for Talgo alone.
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more... Running Talgo at 150kmph does not require much modifications to the permanent way, while enabling LHB coaches to run at the same speed for the entire Mumbai-Delhi route would take considerable time and expenditure. While it is good to upgrade our tracks in the long term, Talgo provides us the opportunity to go for high speed runs in not jsut one, but many main routes of IR with minimal expenditure. Shatabdi's between SBC-MAS, MYS-MAS and many south indian routes can also be upgraded right away.
The unique arrangement of the Talgo coaches means that the impact of longer rakes on MPS is much lesser than what is seen with traditional ICF/LHB coaches. So, even a much longer Talgo rake can be still run at 150kmph meeting the passenger capacity requirements, at least for the Shatabdi trains.
And the coaches are also more durable and crash-worthy in high speed operations due to the Jacob's bogie and the lightweight Aluminum construction.
Running the together with freights and normal trains is definitely a problem that has to be dealt with properly, but otherwise, it looks like a good bet for IR.