No, not usually. 😉 Apple usually charges a premium for their RAM, and using 3rd party vendors is much more cost-effective. Here in North America at least it always seems like if you buy RAM through Apple you're paying through the nose. Can't speak regarding Oz though of course. 😉
What exactly are you looking at in terms of a RAM upgrade through Apple? Just curious what the details are... Because keep in mind that an upgrade from 1 GB to 2 GB (as an example) is not simply the price difference between the two options - you should factor in the fact that the initial cost of the 2x512 MB RAM sticks is built into the cost of the machine. So technically, you are buying two 1 GB sticks of RAM from Apple as an "upgrade", however do not get to keep the two 512 MB sticks which initially came with your machine. Follow me?