South Street Gallery said a 24-inch by 36-inch painting of the Boston Marathon fetched nearly $2,550, which will all be donated to the One Fund Boston. According to gallery manager Kate Sotolova, the painting was donated by Gloucester painter Charles Movalli, who exhibited in the South Street Gallery throughout June. The exhibit featured 30 real-life paintings of Boston, with only the impressionistic marathon piece up for silent auction. Cohasset resident and avid art collector Tom Hamilton purchased the piece, which features a slew of runners racing among American flags. “We were happy with the outcome, with the price, with the auction result,” Sotolova said.