Costings can't have been done on the new submarines because the program has not been developed yet. That is what the next 18 months is for, work to be undertaken between Aus, US & UK to assess the exact requirements and processes of the program. Once that is done, we will know the costings. I would assume a number of different options, with different costings, will be investigated.
Costings on cancelling the French contract aren't all that relevant. It's going to cost what it costs. The contracts were a mistake and needed to be cancelled. Diesel submarines are not fit for our purpose. If it costs a break fee of $400m, that's still better than continuing with a $90Bn contract that won't deliver what we require for the next half a century.
