Sean,
If you want to do long exposure astrophotography it isnt going to be cheap im sorry to say.
Mount/telescope/camera/guidescope etc you'll be looking at $1000 minimum.
Do some reading and research before you jump into it. It's not as simple as buying a telescope putting it on the ground and off you go. There is lots more to it.
I really think you need to visit an astro society or even drop into BINTEL
http://www.bintel.com.au/ and get a feel for some telescopes and look through them, see what they actually look like.
A list of clubs/societys In VIC can be found here
http://www.iceinspace.com.au/clublistings.html#VIC