Hey, one thing you could do is ask the 
people auctioning off the Sailor Moon Bank cel
on ebay. 
According to their policy, they say that
they'll cancel any bids made by anyone with 
less than three positive responses. Since they've
decided to keep lain's bids, it's possible that
he/she/it has contacted them and is legit. 

It is interesting that Parallax has cancelled
all of the bids from lain on the Noriko death
cel. From an all-time high of $3 050, it's 
dropped to around $200. Oh well, if lain's legit, 
he'll get in contact with him, because he had the
winning bid at the time. 

I hope you get your money.