Regularly rusty metal piece= Cheap fix?

So I've been examining used cars recently and I've noticed that on Honda civic's there's this metal piece that's always rusted and about to fall off. It's near the from end on the inside of the hood, its shaped like half a funnel and looks like some kind of cover because it's placed directly infront of the motor and after the front radiator. It might be part of the motor.

Anywho, If you're familiar with honda civics and know which piece I'm referring to I'd just like to know if it would be a cheap fix to have this replaced..