If you have a look at the list of Virginia class boats on order by the USN - I suspect Australia might be waiting a very long time to get it's hands on new boats.
I'm sure the RAN would be drooling at the thought of the Virginia class but $2.8bn versus $2.4bn per unit for the Astute.
An extra $1.6bn overall at least for buying American.
The Astute is slightly faster submerged - and depending who you believe, has a more capable sonar.
If they are going with the US I wonder whether both navies would consider Australia acquiring a few older block one or two boats - and the USN replacing them with more block 4s and 5s.
Australia gets a still very capable boat or three early and cuts down on the capability gap, the US replaces them with the latest and greatest.
Zut alors - the French really have les merdes with us - French ambassador now referring to `treason in the making.'