The 16GB model costs $399, while the 32GB variant is $449. (The US pricing starts at $US349, which is effectively equal once you convert currency and add GST.) You can choose between black or white.
Google says the phone will ship within 1-2 business days (most likely from South-East Asia); you’ll pay $19.95 for shipping. Update: The first batch of 32GB models has sold out.