Indian Navy Crew Undergoing Training Onboard K-152 Nerpa Attack Submarine

[jha]

4 SSN in 10 billion $ is too costly for a country like India but we should not forget that we are also placing order for just 6 SSK in 11 billion $.

Not sure what are you trying to say. But the projected Cost is inclusive of the infra cost.

 

[MST]

2.5 billion$ / sub is too much but they are claiming it to be bigger than Astute, well thats good. But cost is still high considering, research and labor and raw material, all are cheaper in India.
It is estimated that cost of 1 graney class to be 1 billion $, although some sources says it is 2 billion $ but still both are cheaper. While HMS astute costs around 1.2 billion euro and baracuda cost around 1.2 billion euro but all of them are cheaper than what is planned by India.

4 SSN in 10 billion $ is too costly for a country like India but we should not forget that we are also placing order for just 6 SSK in 11 billion $.

I am wondering if they will cost the same in year 2021. I think the cost you have given is for 2010 or before (a source will be appreciated). You should add more than 10 years of inflation to the price as well. Considering infrastructure setup as well I don't think the cost of Subs is too expensive.