Weapons made of precious materials are more expensive and sometimes have special effects. You can make metal weapons out of any of these materials except darkwood, and wooden weapons out of darkwood. To determine the Price of 10 pieces of ammunition, use the base Price for a single weapon, without adding any extra for Bulk.
Low-grade items can be used in the creation of magic items of up to 8th level, and they can hold runes of up to 8th level. Standard-grade items can be used to create magic items of up to 15th level and can hold runes of up to 15th level. High-grade items use the purest form of the precious material, and can be used to Craft magic items of any level holding any runes.