I've noodled around with the idea of a Resource roll. It starts at 11- (or 8- if the character is poor), with a +1 to the roll for 5 points. Normal expenses (food, rent, equipment maintenance) don't require a roll, but major expenses (new weapons, armor, magic items) would. Expensive items would have a penalty to the roll. Treasure would be abstracted as 1-time bonuses to the roll.