As billionaires get buffeted by the uncertainties of financial markets and new collectors are minted every day, auction houses are learning not to ignore material with fewer zeroes on the price tag.

Competition for the huge sweet spot that is the middle market has been heating up ever since Christie’s and Sotheby’s raised the buyer’s premium to a fat 25 percent of the first $20,000 (£10,000) last September. A few smaller outfits, such as London-based Bonhams and Bloomsbury Auctions, stuck with 20 percent, and they have been jumping for joy, sensing that the auction giants might shed a part of their lower-end business. Read Full Story