Now that the Lumia 920 has been announced, previous Lumia models will start going down in price. Take the Lumia 900 for example. You can score that bad boy for $399 today.
I'll admit that I haven't heard of the Think Of Us online store before, but there's a first time for everything. Think Of Us have the Lumia 900 for $399 (plus ~$20 shipping) today. That's down from the current RRP of $699 — a saving of $300. [Think of Us via OzBargain]