Some voltage regulators behave in a way that reduces ripple. I get the impression that careful design of even a simple power supply can result in an output that has low ripple. I've seen the ripple reduction specs that are used to decribe the common regulator ICs but I don't have the skills to interpret what I read, at this point anyway. I might be correct in concluding that the ripple reduction features of some IC's might reduce the demands of a filter capacitor. As suggested, the price of large caps is up there - many ICs and associated electronics are cheap.