I live in Cairns too, I bought my first scope a few months ago now from Suncoast optical down on Spence Street. I would have loved to have bought one off the net and everyone here gave me great advice about what to get etc but i'm a tactile person and really need to see and touch what im gonna get before parting with my cash. I bought a Celestron astro master for $600, Its great for the moon and i've also used it for Jupiter. I think it really depends on your budget, for sure get the best for what you can afford but the scopes just keep getting better and better and pricier and pricier so just figure out your price range before you even look or you'll end up spending way too much. I bought this one to test the water, I didnt want to spend more than that incase It wasnt something I would stick with but its been great and i'm ready for upgrading to a 10" Dob. If your interested in a 2nd hand one let me know and i'll pm you the details
