Lore: Commerce
Commerce, sometimes called Mercantile, is the understanding of buying, selling and trade. This may be knowing the innate value of an item or good, to knowing when a good is being oversold or short changed. It may also involve the history and/or current knowledge of various trades, such as a plane's Spice Trade, and where to find how it flows.
Commerce also differs from Capitalism for a multitude of reasons, even though much of Capitalism heavily involves Commerce. One key difference is the penchant of evil and corruption.