Good luck!
Barleyman had some second handies last time i was there. There is a brew shop at kogarah who mainly supplies k&k gear but i went through last week and poked my head in and looks like he has 2nd hand kegs in stock too.
I bought a new keg king one for 120 recently and they are heaps better than his old ones. I thought that was better than spending 60-80bucks and having to replace seals and clean and worry about leaks etc.