Although you have some valid points you are wrong about the FDR this has nothing to do with first of type but a function of over 5700 kgs aircraft
I suspect other costs relate to Australian provisions for aircraft not the actual type certification.
Look up what special provisions the UK CAA have for Citation II type and you'll find you have to have the strengthen belly mod for example.
The old days of perks for the boys are over re Aust certification but complying with our generic requirements remain in the same way as other countries
Why not simply operate the aircraft on the FAA register then you only have to comply with ADSB and the simplified FAA paperwork and approvals