Hi Mick,
well guess what - they're right
Celestron and Meade, and probably others as well, have very strict rules regarding shipping scopes into Oz. They have distributors here, and the last thing they want to do is tread on their toes by competing. Their prices are excellent as you say, so you can imagine how choked the resellers here would be if they found that happening.
However, if you're adamant, you could very easily ship one to an address in the USA and have it forwarded from there to you. There are companies that do specifically this type of freight forwarding. Don't forget though, any warranty issues would then be with your supplier, not the local dealer here in Oz. That sort of puts a bit of a dampener on the idea doesn't it
Not like buying a Canon camera with a (supposedly) worldwide warranty
Cheers,