It may have been covered in the previous 12 pages, but if not there are a few companies/websites advertising used tractors for sale.
These are generally only up to 20 years old, good brands, free Aussie delivery, and half the price of real ones.
There was one in Rockhampton called Russel's machinery but no phone answers and a drive-by of the address shows a vacant site far too small for the advertised tractors. Another one based in Melbourne with the holding yard at Boulia. Google Earth images of the addresses show part acre industrial sites. One called Efarmtractors is based at Eden, but a phone call to a neighbouring business advised that address is bushland.
The photo's shown have different backdrops and look to be from dozens of areas, but different websites have some of the same machines.
These people will take a deposit but are booked out 3 to 4 weeks in advance for an inspection quoting virus concerns. If you want a 6 year old 50HP John Deere with a loader and backhoe for $18 000 look carefully.