There is plenty of ways to get track time, Supersprints are great and dont cost the earth, and you get official lap times out of it! Also practice days are great. You dont need to hire the track at all.
if you join the ARDC you can do eastern creek, for next to nix,(120 last time I asked about a practice day) You will need to be a member of a cams affiliated club, like ardc or the Small ford car club of NSW. and pay 100 to cams for a year long l2speed licence that you can use for all sorts of events. so support the tracks, the cams federation and the clubs.
Wakefield is always an option too.