Metropolitan Opera General Manager Peter Gelb is having trouble cutting costs. While all the company’s nonunion workers took a pay cut of 10 percent, Gelb has had to blow some coin on the disastrous “Tosca” after audiences booed its debut. “They’ve spent $50,000 attempting to relight the dreary production, to no avail,” said one source. But an even bigger waste was the hiring of Finnish baritone Juha Uusitalo, who pulled out before the season even began. “Gelb had to have him as Scarpia and bought out his [Finland] season’s contract — a disaster,” said our insider. The Met attributed his dropping out to “illness.” “His performances were canceled, and they’re now paying him not to sing in both Scandinavia and New York,” our source said. A Met rep said, “As a matter of policy, we don’t comment on production costs or artists’ compensation.”