Those who have no other choice or who want to can still paper-file their returns and use paper forms.
As for the savings, it's hard to give you a number, because there are many factors to consider. As you know, paper-based communications are more expensive: there are postage costs, document storage costs and mailroom costs. Paper-based correspondence has real costs.
It's really tough to answer your question and tell you exactly how much the transition to an electronic system cost.