Traveling merchants with a random inventory to sell. They could appear at random times and locations throughout the world. It could be an amazing way to get weird or out of the ordinary items that are sold or found in other regions. These nomadic vendors could have special items that only they sell, such as rare housing items, different looking weapons, jewelry, etc.

On the note of random events, It would be neat to see some weird monsters appear at random within the world that drop different ingredients and items that you wouldn't gain anywhere else.