Our trade-goods catalog covers cloth, leather, hides, metal and stone, herbs, elemental materials, enchanting reagents, jewelcrafting stones, parts, and the Retail-era optional and finishing reagents that feed crafting orders. Each subclass corresponds to a profession's primary input pipeline, so a quick glance at the subclass column tells you which tradeskill the item feeds.
Materials are the clearest patch-cycle market in the game. A new expansion patch sends old-content materials cheap and new-content materials expensive, and the transition shows up in the history charts weeks before it is obvious in the in-game UI. Supply lines differ per subclass: cloth supply follows leveling traffic through humanoid zones, enchanting materials arrive by disenchanting unwanted gear (so their supply moves inversely with gear prices), and elemental materials — motes, primals, crystallized elements — gate enough classic-era recipes that primal trading was effectively TBC's spot market.
Click any material to open its price-history page, which shows current minimum buyout, average and median sale price, and total quantity listed. The realm selector on that page is especially useful for materials, because commodity prices diverge more between realms than gear prices do — the same ore can be plentiful on one server and scarce on another, and the chart makes the difference explicit. Retail narrows that divergence for true commodities, which trade in a region-wide pool rather than per realm, while the classic editions still price every stack realm by realm — so the selector does its heaviest work on classic charts.