No B-2's available for Australia to buy until maybe when a sufficient number of B-21's are available for USAF. In general regarding B-2 maintenance and upkeep (excluding LO maintenance), the aircraft for it's design complexity has been and is pretty reliable from the aspects of avionics, hydro, fuel, landing gear, mechanical systems, etc. This is from experience being involved with the B-2 for 10 years involving subsystems development. The B-2 still has a lot of life in it, beyond 2030, it's not even close to approaching it's end of structural life that's for sure. If the USAF can upgrade the B-2 with B-21 LO and if allowed, the Aussies could potentially purchase some, the cost, that I don't know.