On sale day, an auctioneer announces a 10% buyer's premium that appeared in none of the advertising or posted terms. This is
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Answer: A
unfair to bidders who relied on the terms.: Correct. A buyer's premium changes every bidder's price, so it must be disclosed in advance; most licensing states require it in advertising or terms, and springing it on sale day misleads bidders who came on the published terms.
proper, since block announcements prevail.: Sale-day announcements may clarify or correct terms, but they cannot fairly add a major undisclosed cost.
proper if it matches the firm's usual rate.: A customary rate is still a new charge if it was not in the advertising or posted terms; bidders cannot be bound by what they were never told.
proper if the seller approves it.: Seller approval does not cure unfairness to bidders who relied on the published terms.
Buyer's premiums are typically required to be disclosed in advance in advertising and terms of sale; a surprise premium misleads bidders.