From back cover:
Dune Trader explores the lives of the people who are the lifeblood of Athas. The major merchant houses of the Tyr region are described, as well as minor houses, elven merchant and raiding tribes, and the mercantile tendencies of all the races of Athas. The personalities who drive these houses and tribes are detailed fully within these pages.
A new character class is introduced here - the trader class. The DM receives complete instructions on how to run a trader-based campaign, and the players are shown how to play trader characters and start their own merchant houses. The most vital and exciting challenges on Athas await within this book!