There's no point to that, unless you're talking about a loan system. While such a system would be cool, it is fraught with problems. If not mediated by a server plugin, it would be dependent on the honor system, and that just wouldn't work. And who would throw in the first few million noobs to get it going? If mediated by a server plugin, what happens when you default? And how does the server not implode with lag?

A regular old bank where you store noobs just seems to solve a problem that doesn't exist.