These guys are repeating a sale (see http://www.ozbargain.com.au/node/46443).
I know its not everyone's cup of tea to get a used computer, but I think it is a good offer if you want to get a bunch of cheap computers that can do the basic stuff.
they give 1 year warranty with all the used gear they sell, so it is a safe bet. their shipping rates are quite reasonable given its a heavy item.
Its easily upgradable: has 4 slots of DDR2 memory, takes any SATA HDD, and can take a PCI express video card.
Here's specs for it!