Taken from The Secret of the Rosary by St. Louis De Montfort.

It is written: "Give and it shall be given unto you." To take Blessed Alan's illustration of this: "Supposing each day I give you one hundred and fifty diamonds, even if you were my enemy, would you not forgive me? Would you not treat me as a friend and give me all the graces you were able to give? If you want you to gain the riches of grace and of glory, salute the Blessed Virgin, honor your good Mother." "He that honoreth his mother (the Blessed Virgin) is as one that layeth up a treasure." So every day do give her at least fifty Hail Marys - for each one is worth fifteen precious stones and they please Our Lady far more than all the riches of this world put together.

And you can expect such great things from her generousity! She is our Mother and our friend. She is the empress of the universe and loves us more than all the mothers and queens of the world have ever loved any one human being. This is really so, for the charity of the Blessed Virgin far surpasses the natural love of all mankind and even of all the angels, as Saint Augustine says.

One day St. Gertrude had a vision of Our Lord counting gold coins. She summoned the courage to ask Him what He was doing. He answered: "I am counting the Hail Marys that you have said; this is the money with which you can pay your way to Heaven."