Buying your way into heaven?

Paul Vitello, reporting for the New York Times, describes the return of Indulgences here . For those versed in Church History, we remember that Luther took to task the Catholic Church over the selling of these dispensations. Indulgences are avenues to avoid time in purgatory or at least reduce the amount of suffering one must endure. The Vatican is making it clear that these indulgences are not for sale, however are available for those who will make charitable donations. The implications of this move are seismic in nature. Evangelical theology teaches that forgiveness of sins is final at the Cross of Christ. Christ paid for every one's sins once and for all. I wonder if people find Indulgences appealing for it gives us the ability to influence God's forgiveness?