I was going to say the same, no one comes back!. Just been to OZ last few weeks on business. Perth, Brisbane, Adelaide and Sydney. Everyone I met was an ex pat. No one wants to return to blighty once they go. Sun shines too much.
Reason GTVs are so expensive in OZ is EVERYTHING IS EXPENSIVE THERE!!!! Crazy prices since I was there last 10 years ago. Salaries are 2 or 3 times UK salaries which evens out as everything is at least twice as expensive, apart from petrol, which is a bonus if you have a V6. Most cars are 4L + there.
Many OZ manufacturing and oil companies look to the UK as a low cost design base. Who would have thought that in rip off Britain.
If the GTV stays in the UK sell it now whilst its roadworthy or store it with the view of abandoning / giving it away if you stay in OZ. It will cost you half the cost of the car to come home and sell it.