My son bought a place a very good suburb in Melbourne with a similar story 2 months ago.
The owner withdrew the auction 4 days prior and was taking offers, apparently he won it by 3k, which was about 100 - 150 lower than what I expected. The agent said that the owner was selling both her investment properties and moving back to China.
Also said that 30 days settlement was the clincher.
On settlement day we rang the agent and told him that all her furniture was still in there, Fridge , televisions ( 2real good ones ) beds, mower, whipper snipper, washing machine, dryer all cooking mixers , cupboards all full of equipment basically everything a house needs.
The agent said that she was selling it fully furnished, as is .
I had put it down to having something to do with Evergrande, I haven't heard or seen anything similar until reading your post.
I really couldn't understand why the sudden rush to sell, prices at other auctions in the area are are still getting anywhere between 10 and 35% better than advertised. Go Figure
