^that, exactly.
It probably does not matter what vehicle is purchased when a low purchase price is a necessity, and there is no guarantee of parts availability at any remote or semi remote area.
Any vehicle in that price range from major manufacturers have no shortage of parts, and they are all only a few days courier away. The network of Euro wreckers is extensive, and despite all the scary third person stories, unless the part is off a far rarer or more modern vehicle, don't require second mortgages.
The simple fact that you can buy a running unregistered vehicle for mere hundreds of dollars means that parts off them will not cost thousands.
Any decision the OP makes should be based on fact, and not urban myths, and unless the girls buy a BMW X5, repair price comparisons are not helpful.
The chance of a Falcon breaking down and requiring a new engine or transmission is real, as is any car. The chance that it happens in an area where there is spare engines and transmissions available is hopeful at best. The likelihood is that parts would need to be sourced and couriered to a workshop.
The vehicle of choice is a decision I would hate to make, but being limited to basic Australian vehicles MAY not be the best way to go.
I replaced my semi reliable Holden Monterey with a SsangYong Rexton turbo diesel auto, and despite all the stories about Korean rubbish, it is going well, it is economical, it is comfortable, and surprise...plenty of parts are available if needed.
Whatever happens we will never know whether the choice was the best.
Cheers