2001 Chevy Cavalier Oily Spark Plugs

I'm taking care of my husband's car while he is in Iraq and I don't know much about cars, so when I take it in and the mechanics tell me something is wrong, not sure if they are just trying to rip me off or not. They changed the gasket because oil was leaking and then they said the spark plugs were oily and would need to be changed for it to run more efficiently, particularly with gas mileage.

I didn't want to say yes to it at that moment, so thought I would do some research and also ask if this is a necessity.

Would be grateful for any advice.

Thank You!