People somehow get the idea they can haphazardly choose when they will be obedient, or disobedient. And when they choose to be disobedient, they somehow think they can tell God when they have paid enough, or suffered long enough. Don't be fooled by such a scheme of the devil. If you owned all the resources in the world, that would not be a sufficient payment for disobedience. Earthly means not sufficient to pay for sin.
Disobedience is sin, and humans have no ability to pay the debt created by even the smallest act.
In the case of David, one could easily make the case God went easy on him. Is the death of 70,000 people sufficient to repay one sin. Not even 70,000 times 70,000 would be a sufficient amount. We must drill this fact into our minds. As long as we are content thinking our small acts of disobedience are no big deal, we will never understand the holiness of God.