Ours is generally somewhere in between $250 and $300. We've got a 3 bed townhouse, with just the two of us (for a few more weeks anyway) but neither of us is home during the day.
I think the appliances you use really do make a big difference, our washer, dryer, fridge, aircon/heater etc all have high energy ratings and I think our bills are quite cheap considering how much we use them.
We're actually pretty bad when it comes to electricity consumption, the computers are never shut down, DH constantly has the LCD TV on (they apparently gobble power), the aircon/heater is on most of the time (except for a few weeks a year when it isn't necessary) and most things we don't turn off at the switch. We do however have gas hot water which I think makes a difference...

