We run a sale every fall - $173 for the first 3000 sf (almost all of our clients have 3k to 5k sf lawns.) That covers aeration, seed, and starter fert.
It's kind of tight, but most of them are on our program anyway.
I try to stay away from straight aerations but end up doing a dozen or so. Those are usually when somebody calls while we're out and about and their house is close to where we are at. So it's kind of gravy. We charge $75 for 3k and $10 for each additional k.
I have no idea how anybody could do it for less. I've seen cube vans full of Classens and illegals, and I've seen bluebirds in buicks pull up, so I guess somebody has figured out how to make lowballing work.
I just scratch my head and don't worry about it.