A Trader subclass for 5E

In the deserts of Athas, the setting of Dark Sun, great merchant houses ferry the goods needed to survive from city to city. The characters that serve a key purpose in these merchant houses are the Dune Traders. 

In the post-fall wilderness of Draconis, trading goods between communities has become essential to survival. In the Plaguelands, the powerful faction known as The Guild is only just now emerging on the forefront. With a strong presence in Trade Town, the Guild is a key organization in the supply, survival and travel needs of the communities of the Plaguelands. With dozens of thieves, assassins and vagabonds in its employ, it is also a network of less reputable individuals. None are so valued however as the Traders. 

TRADER is an archetype for the 5th Edition Rogue class. Traders are rogues that specialize in merchandise, profit, social contacts and negotiation. Without Traders, the economy of the post-apocalyptic wilderness communities would quickly collapse. They provide a strong network of tightening economic dependency between the communities. As a Trader, you quickly grow into an economic linchpin of your party.

Bonus Proficiencies

At 3rd level, you gain proficiency in two skills or artisan's tools of the following list: Deception, Insight, Intimidation, Persuasion and Calligrapher's Supplies, Cartographer's Tools or Jeweler's Tools.

Fast Talk

At 3rd level, you gain the ability as a bonus action on your turn, to make a Charisma (Persuasion) or (Deception) check, opposed by the target's Wisdom (Insight) to talk your way out of sticky situations. You can use your fast talk in bargaining situations or to gain advantage on your next attack roll.

Trade Tongue

At 9th level, you learn two additional languages. You are implied to have learned these languages in your career as a trader. They can be common as well as exotic languages.

Exceptional Contact

During your adventures, you have made contacts with various communities and organizations. At 13th level, one of these contacts - either a warlord or guild leader or community leader - develops into an exceptionally strong ally. At any time, you can invoke this ally's aid in a situation. For all intents and purposes, the ally acts as if under the influence of Charm Person. 

Leverage

At 17th level, your contacts, trading partners, personal standing and credit and personal wealth are such that you can immediately procure any service (including spellcasting services, as per the PHB's chapter on Equipment) you want. In addition, you can maintain an aristocratic lifestyle at no cost and suffer no expense for food, drink and lodging.