All dealers calculate the spot plus their own fabrication and
cutting charges. So what you need to compare for yourself is the
different suppliers fabrication fees and then the shipping policies.
all are about the same - I recommend Hoover and Strong, I live in the
eastern half of the US. Also realize tha some secondary vendors buy
from, say Hoover and Strong and resell the products from that
manufacturer (olders for instance, and the secondary vendors are
Jewelers Supply Houses like Contenti, Kassoy, Livasays, Rosenthal’s
etc.). Bottom line: all manufacturers have their own colour formulas
for golds, and matching solder colours to metals is a point to
consider as is customer service (H&S wins in that department in my
experience with them over many many years), and product quality.
Stuller looses in my experience and the rest fall into the middle of
that continuum. D. H. Fell is nearest Stuller, Hauser and Miller
second to Hoover and Strong. No doubt everygoldsmith will have a
differeing opinion. Ultimately the research is yours to do.