Well, if its any consolation, in my experience, quilts in books call for enough yardage for squaring up, mistakes, etc. I made a quilt from a book once and was kind of annoyed at all the excess. I would have preferred not to spend that much extra on fabrics that weren't really "my" colors.
Seems like another pattern I made from a book called for way more than was actually needed, but I may have switched that one up a bit, so it may have been my own fault. I don't do patterns from books/magazines often.