It is usually considered that special graces are obtained for whom the Mass is said.  Masses are offered for many reasons (i.e. for the repose of souls in purgatory, in thanksgiving for blessings received, etc.).  These graces are freely given by our Lord, by His will alone, regardless of whether or not a Mass intention is accompanied with a stipend (what you offer to the priest). To be clear, Catholics do not "pay" for a Mass. Rather, by giving something of ourselves, be it our time, talent, or treasure, we associate more intimately with Christ, who offers himself in the Eucharist.

To view the schedule of Mass intentions, CLICK HERE.