Whats the official price on cx8?

Yes there are/were issues with Mazda Skyactiv Diesels, unfortunately these cars are being sold as 'daily runabouts', salesman says will not have any problems...They are very wrong (I am an ex Mazda Manager).
No 'clean' Diesel Engine car should be used as a suburban runabout as they need long distant use (about 45 minute one way once every week) so the Diesel Particulate Filter deposits can be burnt off.
If car is doing constant short trips you get Oil Level (Dipstick) Rising as Fuel is being dumped past Piston Ring as engine is not getting hot enough.

If you are doing lots of short trips I suggest you manually do a DPF Regeneration of DPFilter do the following....Must park car in well ventilated area with plenty of fuel in tank.

''Within six (6) seconds of starting the engine, press and hold the "TCS OFF" or "DSC OFF" button for 2-5 seconds to start the DPF Regeneration.
The engine idle will raise to 1750 rpm for 15-25 minutes until the DPF Regeneration is completed.
NOTE: Do Not hold the "TCS OFF" or "DSC OFF" button longer than ten (10) seconds or DTC C0089:64 will set. The glow plug indicator on Dash will flash during this manual DPF Regeneration process.''

But Yes, Australia needs a USA 'Lemon Law' that works, relying on ACCC is just too difficult a process.

Read this on the accc website