RFIDs, a library thing

I've been helping out a library to retrieve books from a floor that was damaged by storm a few weeks ago. Things went pretty fine at the beginning, finding books by the Library of Congress call numbers, taking them back, putting them on trolleys, giving them to the readers... Until one night, when I was totally exhausted, I had a thought about the RFIDs used in libraries. Wouldn't it be sweet to track down a book with a 'book detector' rather than going through all the shelves?

Now, RFIDs, this page from ALA explains the basics:

http://www.ala.org/ala/pla/plapubs/technotes/rfidtechnology.htm

However, a $0.85 ID for each book means it'll cost a lot for a library with thousands books in its collection.