Paris gallerist Jocelyn Wolff is always stressed before Art Basel, he told me over the phone from a café in the French capital earlier this month. In fact, by his calculation, he has suffered 20 years of pre-Basel stress, less from worrying about the vicissitudes of the art market, than from the high participation costs for his small 8th arrondissement gallery. This year, however, he is feeling a bit less anxious than usual, thanks to some fortuitous pre-sales. That bodes well for the flagship Art Basel fair, opening to VIPs at the Swiss city’s Messeplatz on Tuesday.