As a seller, I know that I can change whatever I want as long as there are no bids, up to 12 hours before ending time.
As a bidder, I will safeguard myself against the bidless item "changing" by placing a $1 bid on it so the seller can only add to the auction. I know this violates bidder law #1 but I don't want to pay $90 for a wristband either.