I think it's the seller's right to do whatever
they want to with their auctions.  Maybe the guy
got a good offer for the cel and decided to take
it down.  Then again, it could have been like you
said where he didn't think he was going to get
enough out of it.  I know that a lot of the times
the price of a cel triples within the last few
minutes on E-bay.  If he was worried about not
getting what he paid for it, he should have set a
reserve price...