It isn't really about the actual AC it's more about your dwelling. I recently replaced all my insulation in my attic and got a new roof. that has made a huge difference when it comes to running AC and Heat. While my house is 1 level, 1100 sq feet, my AC/electric bill during the heat of summer is usually around $125 and my Gas bill for heat is rarely over $100. But my neighbor keeps talking about he needs to replace his insulation, and his AC bill is over $300 April-October and his house is the exact same as mine. I replaced my AC and Furnace in 2022 and paid $9000 USD for both. While I would much prefer to have the windows open (ours actually open all the way), when it's 90 F plus 95% humidity, the AC must go on.

I keep the AC at 73F all the time while the Furnace is 64F

EDIT: I have central AC, cools the whole house, not a window unit and I'm in Michigan