Holy mackerel, Susan -- I think I will stop complaining about my electric bill now... ours runs about $200/month (on the "budget plan," so that it's the same every month). That's with an electric clothes dryer and electric stove, but the water heater runs on our hot-water boiler. I thought $200/month was pretty high until I was recently talking to a friend who is on the same power company and she said their bill is about $500/month; and now, after seeing your post, I'm really convinced that ours is not too bad.
The heat tapes are used in our area quite a bit to keep pipes from freezing, but be cautious; a lot of fires also seem to start from them. Do you have any sort of insulation around the base of your mobile? I know a lot of people here use straw bales to help with that. And, as you probably know, let the water run... things get
really expensive when pipes start bursting!
And to think, winter is just beginning...