Central air and heat is pretty standard here in any house built in the last 50 years. Some have all electric, others, like ours, have electric air and gas heat. We also have gas dryer, water heater and stove/oven. It doesn't get that cold here, so our highest bill is around $100 in the winter. The summer, however, is a different story and we get extremely high electric bills, although we do have balanced billing so pay about $130 year round. One thing that helps my bill is programmable thermostats. They go down to about 65 during the day when no one is home and top out at 70 at night. In the summer, they go up to 85 during the day and down to 78 when we are home, although there are many days when the air conditioner works non-stop for that! We have lots of large windows and very high ceilings in an open concept house, about 2300 sf, so it's not that energy conscious.
By the way, I paid $2.99 for gas today, up from $2.74 a few days ago. They announce that oil hits $100 a barrel, and boom, the prices go up. I know that's not that high for folks in other parts of the country, but remember, it doesn't have to be transported that far to get to me. There are refineries within 30 miles of my house!