G'day Andy,
Not too many replies here yet. But welcome back into the great KDX scene. Like you, I had an older model once upon a time (KDX175) and loved it so much that I came back for more, about 20 years later.
Here in Melbourne we have the
Trading Post which may have a Sydney equivalent. I used their online version to search for KDXs each week until I found one. There aren't too many for sale at this time of year though, I notice (usually lots).
I suggest you try to find such a publication in Sydney, or go into the newsagent and buy those motorcycle trader magazines that they sell there. You will hopefully find more for sale once the weather starts to warm up a bit.
Good luck.