Gamespot interviewed Game Director Ion Hazzikostas who confirmed the Trading Post currency won’t be sold as a standalone product.
On June 14, we’ve datamined assets showing various Trader’s Tender bundles and we thought the currency would become available for sale at some point through the in-game shop. However, Game Director Ion Hazzikostas confirmed via Gamespot there are “no plans to sell it as a standalone product, but it would make sense to offer various amounts of Trader’s Tender as part of various bundles, such as expansion deluxe editions.”
You can read the full interview here.