It looks like Telstra are clearing out some stock getting ready for SGS3 and potentially the iphone 5. There are specials (by Telstra standards) on the iphone, galaxy note and galaxy nexus.
Obviously Telstra are not as cheap as Virgin Mobile, Vodafone or some of the other discount providers, but overall their nextG network is worth paying a little extra if you don't live in a metropolitan area.
I thought Optus has an exclusive for the SG3 in Australia?