How do you know when to repair the timing cover w/valve and cover gasket? on 2002 Toyota Camry

Due to a small oil leak detected during a minor service, the repair man advised I should change the timing cover with valve and the cover gasket.

Asked by for the 2002 Toyota Camry
if you dont believe him get another opinion. if you do this repair, replace the timing belt, pulleys, tensioner, seals and water pump.

the cost is 700-800.

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sorry did not read the whole statement, if it leaks between the cover and block you only need to replace the gasket. and you may even be able to stop it w/gasket sealer as there really is no pressure there.