I saw this and thought I would chime in. I don't know how much you anticipate Amazon discounting this item (if they carry it), but I can't imagine it being more than 30%. I checked a few of AEG's items on Amazon and saw some for 30% and a few for 32%. I don't know the extent of a discount from Share the Love either. I just wanted to point you guys at a few other options.
If you care to preorder this monster of a book.
DCBS has it for 35% off to the tune of $65 (figure in shipping to make sure that you'll be getting a good deal).
G-mart has it as well, but it looks to be about 30% there (rough $70). There are a few other preordering sites around apparently. If you click them, you'll notice they are primarily for comic books, but they contain the RPG items being solicited that month as well. I just saw this and wanted to share an option. I'm not affliated with either store, but I can't imagine getting much of a discount than that (though Amazon's free shipping may tip the scales, you're call).