Hi,
Celestron dealers in the USA are forbidden contractually from shipping Celestron products to addresses outside the USA, in order to protect international retailers (such as Australian stores which charge much higher prices).
To obviate this restriction, you can either get yourself a US street address for the US retailer to ship your gear to (either a friend, or one of several online services which will do this for you), or use a buy-it-for-you agent such as PriceUSA.
Be aware, however, that if you go down either path, you will have NO warranty coverage from Celestron (there is a clause in their warranty that specifically deals with this circumstance).
If you happen to physically be _in_ the USA, pop in to buy a scope, and then ship it home, as long as you can prove you were there and bought the scope in person in the USA, Celestron will honour the warranty.
There's a reasonable collection of (and variable reviews of) various address provision, repackaging, and buy-it-for-me services here:
http://www.nevershoppedout.com/mail-forwarding/
Good luck!! :-)
(I'm currently in the process of using Bongo International to acquire a C8 with FL reducer and laser from Oceanside Photo & Telescope, all for <$1,300 AUD including shipping).
Cheers,
Chris