This mural is actually individual vaults or crypts to hold your ashes after you have died. Divided into parts, you can choose which part of the mural you wish to have your ashes behind (e.g. D-5).
These vaults are being offered at a price of $6,000 pesos cash up front and, after which, a small plaque will be placed in the lower corner of your mural piece with your name and appropriate dates (the Padre also said that these usually sell for abut $10,000 pesos).
You can purchase your crypt at any time now - the Padre will be available to accept your payment - he's getting mine after my siesta!