Gamasutra has a new hosted article by Gregory Campbell about in-game shops in RPGs, and the writer uses Divinity: Original Sin as an example to prove his point.
More information.Divinity: Original Sin is a PC and Mac RPG from Larian Studios in the vein of Ultima VII; that is, a game focused on the interactivity in its somewhat open world. In this article, I explore the randomized shop inventory system, and how to improve it to reduce frustration while keeping the current spirit of the game.