Try Macedon Ranges Observatory -
http://www.darksky.net.au
They have telescope pads (2.5x2m concrete slabs with the SCP conveniently pointed out for you) for nightly hire - $15 a night for an unpowered pad, $20 for a powered pad (if you're in to imaging). If you want to pitch a tent, it'll be another $10 for the night.
I've been up there several times, and the skies are nice and dark, great visibility in all directions, and the host is a keen amateur as well. I also live in the Eastern Suburbs, and it's just over an hour away.
Dirt cheap for a purpose built facility catering to the Melbourne amateur astronomer.
Alternatively, if you're a member of the Astronomical Society of Victoria, you can go to their LDMSS site (Heathcote) any time (you need to ring to get the combination lock code as they change it regularly now because of some vandalism). Heathcote is about 1.5 hours (roughly).
Turbo