this has happened to me too, but it was about 6years ago. I think things are different now.

Seller can still cancel auction (if it is more than 12 hours from the end).  They can remove bids any time.  They can put up the price or change the duration, as long as there are no bids or they removed them.  The only thing that can be done while there are already bids is to add postage or payment options.