One of the nice things about his books is that all but the most recent are available for free download online. The first five can be found here http://www.lsccweb.org/BillBugertBooks.php Volume VI on the issues of the Philadelphia mint after 1852 isn't out yet. They really are a fantastic reference.
Well if you are fixated on a particular series it give you an excuse to keep buying them. First you try and get all the date/mints, then you try to get all the varieties, and if you are looking at a coin and you have that date, and you have that variety, do you have that die stage? (John Wright expressed a similar thought "I have that date, and I have that variety, and I have that die stage.......But I don't have a GREEN one!" Any excuse is a good excuse.)