The solution seems to be limited release of your work, or demanding a higher commission, upon publication. Is that realistic? I don't know. I'm a Writer, but not an author of novels. If its not realistic, then it seems an issue for The Writer's Guild to take up with Publishers, because this Author should no more beef with Bookcrossing, than she should with...say...Goodwill, for instance.
As a final note, it is important to realize that many people keep Permanent Collections. I, as a true Bibliophile, will always purchase a copy of a book to keep, in case I want to read it again and again. My money is stuffing Anne Rice's, Tom Robbin's, Hunter S. Tompson's, and SARK's, Shel Silverstein's couches. In some instances, I requested the books as gifts. In other instances, the books were so good that I bought them as gifts. After I read, "Little Altars Everywhere", I knew that every girlfriend on my list needed a copy; therefore, every girl on my Christmas list got a copy...full price.
Some thoughts for you to pass on to the Author.