Now that we have our schedule (and learned that all the Legal Rhetoric sections use the same book), I was able to buy my books. That was about $500 distributed across Amazon.com, the American University bookstore, and some discount bookseller who seems to be the only one capable of shipping the last book in less than 2 months.
I also bought a backpack for about $80. It has seventeen pockets, including a padded computer section with a divider. (I guess that’s so I can carry two laptops or my laptop and my iPad.) It holds 24 liters according to the label. That should allow me to carry giant casebooks for class. I believe it also expands into a two-person tent in case of rain, but that may have been a feature of one of the other 10 backpacks I looked at.