Thanks boggart! We double-checked this one against the original game: Vogen's price list really is 5,000 vesos for each of the ore refines and 1,000,000 vesos for the Dark Crystal. It's the hardest refine he does, so he charges for it. The cheaper route is Spiruna in Orbis, who refines a Dark Crystal for 500,000 vesos once you've helped her out with her quest. Not changing this one, but good on you for checking your sources!