There was much speculation that the buyer(s) may have questioned the attribution even immediately after purchasing and might have felt embarrassment over spending almost half a billion dollars on something that probably wasn’t worth it. Then the recent downgrade of the Gulf Mundi in the exhibition catalog by the Prado seems to confirm judgment that the work is not an authentic original.
If it’s a workshop piece instead of an original then its value is probably in the realm of about $1.5 million dollars.