Doesn't matter what any of us say, until you know what your average monthly or daily usage is, there is no way any information you get will be any good for budgeting purposes.
What you need to determine is how many KWHs you are going to use per day. We use about 20KwH/day, assuming temperatures are moderate most of the day. Cold or hot, then about 30 KWH/day. And even in the same conditions, two rigs will be different because of the owner's temperature preference, the amount of insulation in the rigs, whether you have double pane windows or now, whether you have a heated basement or not, etc.
As said before, if staying either overnight or weekly, electric is usually included. Monthly, usually metered, but not always. Also, some places (towns/counties/states) are prohibited from charging more than what they are charged for power, other places they can charge a higher Kwh rate than what they pay.
Barb