Nothing people would actually buy from an NPC is that high of a price, the person who buys anything for above 100K from that NPC needs to be shot in the foot.

The point was basically what Elphy just said. Even if these can be gotten elsewhere though it makes little difference, scrolls and the like have been high priced in NPCs before, but these prices are far above their normal prices, same with that of dice which are similar to scrolls in how they are used a single time to learn it.