I don't know what the conversion rate is from Auz dollars to USD, but, I think your money would be better spent on an 04 or newer bike.
While this 98 looks to be in fine condition, I notice that it has the conventional 50mm WP extreme forks, which, when tuned properly are probably one of, if not the best conventional forks ever made. However, it is my understanding that they no longer produce parts for them. I am however, relatively sure that you could find parts for the rest of the bike.
However, this was the towards the end of development for that series of motors and they were pretty darn good. By this time they had an oil pump to help with lubrication, and had made improvements to the clutch pressure plate to greatly improve dis-engagement. I am not sure but I think this year had the domino control for the clutch which had the on the fly adjustment which I had retrofitted to my 94 and it worked great.
Just be aware that this series of motors consumes oil, it's just their nature. So you will need to keep an eye on the oil level. In a typical desert race for me, which is about 80 miles, my 94 would consume about 20%-30% of its oil. It was a great bike though, and it ripped!
Just my two cents.
