Goldsmith
A goldsmith might have a wide array of skills and knowledge at their disposal. Gold, being the most malleable metal of all, offers unique opportunities for the worker. In today's world a wide variety of other metals, especially platinum alloys, also may be used frequently. 24 karat is pure gold and historically, was known as fine gold.
DFM Guidelines for Hot Metal Extrusion Process
Nowadays, quite a wide variety of metals are currently extruded commercially, the most common are (in order of decreasing extudability): Aluminium, Magnesium and their alloys, Copper and Copper alloys, low-carbon and medium-carbon steels, low-alloy steels and stainless steels. So obviously as the extrudability decrease the cost of production increases