Optional reagents are Retail crafting-order modifiers, and their value tracks whichever crafted gear currently matters. Optional Reagents — one of the subtypes World of Warcraft files under Tradeskill — gets this table as a focused view: the same drill-down the in-game Auction House browser applies when you filter by subcategory.
Optional Reagents listings clear and replenish at whatever pace the in-game market sets; some subtypes trade in volume, others sit static for stretches. The price-history chart on each row's detail page makes that pattern visible at a glance.
Sort the table by item level or required level to find what matters for your character, or click through to any row for its full price-history chart across realms and game versions.