I'm local to this charger and I've been watching the ComEd hourly pricing for electricity. It's stunning how much more electricity costs now than it did last year. Last year June electricity averaged 3.3 cents/kWh for hourly pricing customers. This year it was 8.9 cents. In the afternoon it's been approaching 15 cents every day.
The higher prices Tesla is charging, while not welcome, are probably largely justified. Especially when you add in what must be a crazy capacity charge to ComEd to reserve 3 gW of power for this location alone.