01 acura integra l.s 2dr hatch

Car has slight oil leak comming from left side of engine.Oil is seeping out of a black round plastic plug, located below valve cover.Car has 124,000 miles I have not had to add any oil. Is this worth fixing or expensive to fix?I was thinking of taking the car to the dealer for the repair if it was not to expensive.Any advice on this repair? Thanks Jack