I don't know the whole story to this, but from 
what the article says, it may not be Mandarake's 
fault at selling the cels! The article says that 
Mandarake is a second hand manga store. Perhaps 
it is their bad luck to accept those cels from 
that so called dealer and attempt to sell them 
with out checking out the background for such 
expensive cels! Of course I may be entirely 
wrong, but what if I'm not?