Something like safes and NPC that are bankers? It would be interesting the perspective of being able to lockpick a safe, though it obviously would require some good amount of skill, and of course, magic locks could be employed. There are many perspectives, perhaps you could even own a goujah and its cart to load goods in. All coming soon(tm) of course.
Now in most RPGs I know currency has no weight, usually as a measure due to the nature of these games, because you are not going to throw money away in the middle of a dungeon(and usually there are no storages in SP CRPGs), for example, where there is no safe place to store this money. A balance between fun and realism is important on such matters.