I'm currently taking an art history class. We were discussing da Vinci last week, and My instructor told us that the Mona Lisa is valued at over 150 MILLION dollars American, and the Last Supper is worth much more, although there's no way to affix a value to it. The Last supper is painted on the wall in thr refectory in the Convent of Santa Maria delle Grazie in Milan, Italy. It can never be moved. Its current condition is poor as it is deteriorating at a fast pace due to the medium used to paint it.
If anyone can tell me how much my painting of the last supper is worth, I would be very happy!
I can't find a record if it being appraised. With that said, I think you could say it's priceless. Nobody would ever sell it. It will never be for sale, so there is no way to affix a price tag on it.