I suppose there is the advantage of not moving to buy the book...The price of petrol (or Gas) is so high its probably going to create a very real ebook advantage all on its own.
Yes I agree the price for that book is crazy. But there are a few good deals on the connect store. I couldn't bring myself to pay that much. To me the beauty of the device is putting my own PDFs on there that I cant be bothered to read on my PC.