Do you have any suggestions of places that ship to Australia? I know Best Buy ships to Guam...but that's not really International. In that price range, it'll be tough.
You should either look for a laptop with decent graphics on an AMD Llano A4-3300M or similar or a laptop with a decent CPU with an Intel Pentium B950 or similar. Depending on what your son does in architecture, it might be more art or more math, so his preference may make your decision for you. You can't get both graphics and CPU at that price range.