Since I believe mods dont allow deals that dont ship to Australia, but this is easily avoided by priceusa ect.
Anyway:
http://www.microsoftstore.com/store/msusa/en_US/pdp/productI….
Lets you choose either 520 or 521, both with different bandwaves
plus free Xbox Music code for 12months
Unlocked phone is 170-180 in store in Australia, so still cheaper after Priceusa/shipto
These are either locked to AT&T or T-Mobile, depending which one you order, they're advertised as no contract, not unlocked. American locked phones are impossible to unlock. This will be a glorified MP3 player unless you live in America.