When researching the Saab-Damen submarine development agreement two interesting bits of information on Australia future submarine selection came to light.Marc Brandt, a Brussels-based industry analyst made two significant comments, probably in late January 2015 - http://www.defensenews.com/story/defense/naval/submarines/2015/02/01/damen-saab-sweden-subs-deal/22535665/ :
The second statement supports indications that Australia is no longer after 12 submarines - just 6, 7 or 8. Choosing as little as 6 submarines is a wise move considering the serious limitations of available Australian funds. Six is also a recognition that Australia has only been able to crew about 2.5 existing Collins at most.
Australia's previous submarine purchases also show a steady reduction in numbers. The numbers of UK built Oberon class submarines (in the Australian Navy 1967-1999) proposed for Australia shrank from 8 to 6. The proposed number of the Collins (operating 1996 – present) went from 10, to 8, to 6).
The cost of 6, 7 or 8 may be for a "discount" of around US $14 Billion, ie. "discounted" from the original figures of US$20 to 30 Billion. Of course figures are academic until the last submarine has been launched, commissioned and paid for.
Japan's pricing for Australia, which will be Japan's first major defence customer in 77 years, will be a highly political matter. Japan sold 4 Matchanu class submarines to Thailand in 1938 http://en.wikipedia.org/wiki/Matchanu-class_submarine .
Part of Japan's estimate might take into account:
1. how much is Australia (as a new junior ally to Japan) prepared to pay? and
2. how much of the cost of Japan's decade's old submarine development program, including the new Lithium-ion battery (LIB) Soryu, can be transferred to Australia?
Japan, can only transfer some of its submarines development costs to one country, Australia. This is unlike Germany's TKMS which can, and has, spread the development cost load among 17 customer countries.