It is not in doubt that Leonardo did complete a painting of this title, the documentary evidence is beyond question. It is estimated that seventy-five percent of all Leonardo's works are still lost and this very strong image could well be one of them. However today's art world contains lots of individuals who know far more about the financial implications of any new discovery than they know about the actual paintings themselves. A new painting by an artist as famous as Leonardo da Vinci would inevitably create a buzz within the art world and it is very likely that values across a range of works would increase as a result.
This painting almost appears too modern for da Vinci. Christ's right hand and sleeve are tightly finished as are the ringlets of the hair, they seem to lack the smokiness of Leonardo's sfumato. The modelling of the face seems quite flat, when I first saw this work, and at first glance, it reminded me of an overworked Modigliani (that is not intended to be a criticism).
I admire this work very much, it just seems so fresh and alive, and would certainly like to own it regardless of who painted it. In conclusion I do hope that this is by da Vinci, who would have been about sixty-one years old at the time it was painted, but I wouldn't bet my house on it.