Are you going with a Sky Watcher or an Orion GOTO dob? All else being equal, the ‘best’ option may be to go for the outlet that has the lowest advertised price for the scope you are considering. So, on pricing, I believe Andrew’s Communications offers the cheapest Sky Watcher GOTO dobs at the moment (
http://www.andrewscom.com.au/site-section-10.htm; see from about halfway down the page) and Bintel offers the cheapest Orions (
http://www.bintel.com.au/Telescopes/Orion-GoTo-Dobsonians/146/catmenu.aspx). Just keep in mind though, not everything is equal, so remember to check warranty info and shipping costs. 