I'm not familiar with the Pinton book, but can recommend "The Theory
and Practice of Goldsmithing" by Dr. Erhard Brepohl (translated by
Charles Lewton-Brain and edited by Tim McCreight) as an excellent
reference book. Still pricey, but much less than Untracht. I
should also mention that the publisher, Brynmorgan Press
(www.Brynmorgen.com), has very generous and flexible discounts for
classes or guilds and don't require huge purchases.
Dr. Erhard Brepohl's The Theory and Practice of Goldsmithing on