How much money is brunozettis last suppers painting?

first off, the last supper was paint by Leonardo da vinci. Conisdering this and that there is literally only 1 orignal painting, there is nothing that it's price can be compared to. This leads to me saying that it is "priceless". IF it were to be at an auction, there is no doubt in my mind that it would bring at least 375+ million dollars (considering The Mona Lisa, his most famous painting, was vauled at 600 million in 2005)