The Catholic Church was not selling indulgences.
Here is a direct quote form Luther's Thesis in the english translation21. Therefore those preachers of indulgences are in error, who say that by the pope's indulgences a man is freed from every penalty, and saved;And here is another one...35. They preach no Christian doctrine who teach that contrition is not necessary in those who intend to buy souls out of purgatory or to buy confessionalia.And here is another one...42. Christians are to be taught that the pope does not intend the buying of pardons to be compared in any way to works of mercy.And here is another one...45. 45. Christians are to be taught that he who sees a man in need, and passes him by, and gives [his money] for pardons, purchases not the indulgences of the pope, but the indignation of God.Try this one for size...76. We say, on the contrary, that the papal pardons are not able to remove the very least of venial sins, so far as its guilt is concerned.What is this saying then...79. To say that the cross, emblazoned with the papal arms, which is set up [by the preachers of indulgences], is of equal worth with the Cross of Christ, is blasphemy.Sounds like buying indulgences to me84. Again: -- "What is this new piety of God and the pope, that for money they allow a man who is impious and their enemy to buy out of purgatory the pious soul of a friend of God, and do not rather, because of that pious and beloved soul's own need, free it for pure love's sake?"I think I would rather believe Luther's document than your take on things.