oil seal on 1991 Mercedes-Benz 300E

I have put a water pump,plugs,plug wires,radiator,battery,fuel distributer,ball joints on the front,thermostat,tires now the oil seal is leaking is it worth fixing and how much money will it be?

Asked by for the 1991 Mercedes-Benz 300E
If it is a slow leak you can keep an eye on oil level until you can afford to fix.