There is only a single location where players are able to purchase Pinenuts in Bulk which is in Timberline Falls. Pinenuts are sold by Scholar Tholin. Now before I get started with telling you the two locations keep in mind in order to purchase any goods from a Karma vendor you must first complete the quest they have for you. That is of course if they have a quest available if not you'll be able to buy whatever they're selling right away.
As aforementioned you can purchase Pinenuts from Scholar Tholin in Timberline Falls. The closest waypoint to Tholin is Krongar Waypoint which is in the northwestern most portion of the zone. Tholin is just south of this Waypoint is a town where you can find Tholin.