Condensation,
Whilst 500hrs command is the minimum requirement to submit an application for Direct Entry, you'll find the average number of hours before someone gets a shot at testing is probably more like 1500 total time (so anywhere from 1000-1300hrs command.) Thats the way it's been in the last year or so, but the hrs may have dropped in recent times as recruiting has ramped up a bit. It is entirely feasible that you'll achieve 500hrs command within your first year in GA, given that you'll already have around 100-150 command from your training.
Most people who are aiming for a career with Qantas generally submit an application the same day they reach the min requirements, whether that be when they get the hours, pass their last ATPL subject etc - i know i did!
All the best with it.
Cheers,
TL