Amy, I believe the term" keystone" originated in the mid 1890’s
by Keystone magazine, later to become Jewelers Circular
Keystone. The subscribers to the magazine complaned to the
editors that customers , while paging through magazines on their
counters, were able to see dealer costs.
The term keystone was easily recognized by those in the jewelry
trade and came to mean that the price quoted was twice the
wholesale cost. “Triple keystone”, therefore, meant that the
quoted price was 3 times the wholesale cost.
Now the reasons retailers use triple key pricing are many and
varied, but thats another story - which can actually lead back
around to the discussionsabout “gold pricing”. Johann in mpls
Minneapolis Community & Technical College