this month ours was $340!!! we live in a bedroom townhome (upstairs/downstairs), about 1100 sq ft. it's never been this high, and the lame things is that frankly, it's still hot in our house, so much so that i have to spend the afternoons downstairs with the baby, because i am afraid he's going to get overheated upstairs. i live in texas.
i try to be careful about turning the lights off etc, but we can't go without ac, especially with the baby. he's pretty hot natured, and almost never wears clothes as it is.
i can't wait until we can afford to move into a home of our own. i hate our apartment. it's way too expensive ($805 a month, poorly insulated, and i hate stairs.)