“In the lexicon of modern and contemporary art fairs, collectors recognize Art Basel as the biggest and the best. By the time the fair ends on Sunday some 60,000 visitors will have flocked here to see an international array of some 300 galleries showing more than 2,000 artists. Many will also peruse art in the coinciding smaller art fairs and institutional exhibitions here. But not everyone is upbeat. Dealers are complaining that it has become difficult to sell great works. Collectors are grumbling about the scarcity of top-quality art.”