A quarter century after grunge’s enigmatic rhapsodist took his own life, Kurt Cobain’s iconic cigarette-singed cardigan worn during Nirvana’s 1993 “Unplugged” performance has sold for $334,000. The tattered, olive-green, Manhattan-brand, button-up sweater, which has never been washed since Cobain wore it, came with dark stains and a burn hole. The seller, Garrett Kletjian, owner of Forty7 Motorsports, bought it four years ago for $137,500. The music cable channel MTV began its “Unplugged” series in 1989, recording live performances of acts that generally played their normally electrified music on sparse acoustics. Cobain’s haunting “Unplugged” performance with Nirvana -- recorded less than six months before his suicide at age 27 -- is considered one of the most iconic shows of the series, and was released posthumously.