I mentioned this in an earlier post. After retrieving the potion from the dungon on one occasion, I decided to sell all of my equipment. (interesting note: the potion of dianthrorritis CAN be sold, but it's nearly worthless GP-wise). I ended up with over 500,000gp. When I went into the bank, I got this popup along the bottom:
Note: Larndom law states that only desposits under 500,000gp can earn interest.
It was a fun discovery.