Quite a few flying schools will refuse to train you in your own aircraft. Those that will, will charge you $100 - $250 per hour to do so. Have you spoken to your school about this? This knocks a big hole in what you can save.
My recommendation is that you find a flying school that teaches under the RAA banner. Get an RAA licence then convert it to a CASA RPL, this is only a paperwork exercise plus a bit of instrument flying.
Then consider a GA aircraft and do the required flight review in it to validate your CASA RPL. Again some flying schools will not do flight reviews in aircraft other than theirs. Ask around.
Finally, owning an aircraft requires a lot of research, this will be easier if you have the experience of actually being a pilot. What StickWithThe Truth said re maintenance cost is a common trap that devastates new owners.