Valve cover gasket on 2000 BMW 540i

I just purchased my first bmw 540i it has 107,000 miles.the car runs fine everything seems to be working properly except for the valve cover gasket is leaking a little!How much does a job like this run?Also does anyone know the average mpg?

Asked by for the 2000 BMW 540i
Get a RepairPrice Estmate for the Valve Cover Gasket(s) Replacement using the RepairPal Estimator;

Approximate City MPG: 15, Highway MPG: 23.