For example:
http://www.astromart.com/classifieds...fied_id=735836
http://www.astromart.com/classifieds...fied_id=735887
http://www.astromart.com/classifieds...fied_id=735687
The Canon 350D is already sold but they often come up and are often around that price as a guide.
Even including shipping a little bit of GST on the G11 you'd still have plenty left over from $4000.
There was even an Apple G4 with Photoshop CS2 in it for US$295. Thats a $1300 piece of software.
So the above would be the Orion ED100 for $599 (not sure how much they are here), a G11 and a Canon 350D. All you need is an autoguiding package and you are off.
The G11 is upgradeable as well.
Greg.