Wow, that is a GREAT deal! I haven't been able to take advantage of the amazon deals on the Imperial Shuttle and now this since I have them so hopefully they'll throw up another great deal on the Death Star so I can snag that bad boy.
I think it will only be a matter of time before The Death Star (10188) goes on sale. Over on amazon.fr it is currently onsale for 356.65 €. Reading hothbricks.com I have noticed that amazon.fr has had the same deals on sets above but a week or two prior to them being on sale at Amazon for the US. Cross your fingers that pattern continues.