This.
We have lots of online classes that use only eBooks.
Let’s say the hard copy book costs $200 for the full 20 chapters.
Our classes are shorter and we only cover 10 of the chapters, but not in order - for instance Chapter 2 first week, Chapter 5 second week, etc.
By “editing” the book, the student gets exactly 10 chapters, all ten chapters are used, in order, for the entire term.
The student pays about $50 to “use” the book for just the term (and then access disappears), or can elect to buy the book to download for eternity (to keep it) for $100.
So, if a student thinks they will never use the book again, they only pay a small percentage (probably what they would lose as an used book sale anyway) or they can pay about 50% for the entire book that they actually covered in class.
We do allow a student to buy the entire book hard cover, if they wish.
The other advantage of custom/eBooks is that publishers can update them faster. This is especially important with some books - for example, Adobe Photoshop and Illustrator comes out with new versions on a regular basis. It used to be a pain in the ass to just barely get the new CS3 textbook in, only to have CS4 software on sale two weeks later. Now they can make the minor changes to cover updates and you have a new textbook that covers all the updates in a mater of weeks instead of months.
Yes, school books are expensive, but at least students are now getting content they use in class, updated to the newest standpoint and have the option to “rent” during the class or pay extra and buy to keep. BTW, these new books are in a pdf format that allows them to be read to you - great news for the visually impaired and those to lazy to actually read and want to have the books read to them! Granted, the voice sounds like Darth Vader on Valium but still - having your textbook read to you is not a horrible option to have as an “extra”.
And lastly, you can also highlight, make notes, or click to external links using these books on any computer/laptop/notepad.