plus the RAAF have worked out how to get things past the gatekeepers..
there's certainly no appetite to buy second hand ships from the USN. Despite the fact that the USN has a very very close relationship with RAN and RAAF and have been instrumental in getting gear fast tracked
The RAAF, like the RAF have always been better at staff work than the other services, great for them getting needed capability, bad where the SMEs on the needed capability are army or navy and can't get their message across. The really sad thing is, while the RAAF have been able to maintain, even grow their engineering expertise due to the inherent requirements of air safety, the RAN as part of the defence structure review and subsequent reorganisation in the late 90s saw their engineering organisation was gutted, basically as a cost saving measure and nothing was set up in its place. I can't help but wonder how much of our current issues are at least in part due to this.