Are you building one of
these?
I don't think anything special would be required for a book camera, insofar as the camera. You'll get the best results if you put some effort mounting the camera (ie, make sure it has a tripod mount), getting a proper lighting source/blackout box and some nice optical-grade (nothing crazy) glass to act as a plate/page flattener.
Here are some recommendations in
this thread for cameras. For $550 you could get yourself a Sony RX100 point and shoot. A Sony 5R/TL NEX interchangeable lens camera with a kit zoom lens. Or you could probably get great results for book photography with something cheaper, like a Canon S110 for around $250, but you probably could go even cheaper and get decent results with book imaging.
And with the Canon S110, you can get
hacked firmware that will let you use a remote trigger, which should make the process easier.
More on
DIY book imaging