Aerator value for lawn care

I have a opportunity to pick up a 6’ “Dirt Dog” aerator that I could use on my compact tractor, used for $950. I’m not a comm. lawn service, I only take care of my yard and my church's ground, which has about 2.5 acres. My goal is to have good looking grass on the church property but there is no watering system. I’m no expert so that’s why I’m asking the question, would an aerator be a good tool to have, (Never used one) or a waste of money in this situation.
Thanks
Kid