It really depends on how well insulated your house is, and where you live?? Heating & cooling is the 'killer', in gas and electric bills.
I have a 3 bdrm house - in one of the mid Atlantic states. My bills will run around $200 (a month) in the winter, and $150 - $160 in the summer.
Call the utility companies and ask for a billing history as an estimate. Yours won't be much different
Gas between $60 and $90, Electric from $90 too $ 350 depending on usage, peek and non-peek times, call both providers and give them unit size and sq.ft. and they should be able to give you highs and lows for both, by your square footage and how many bedrooms and people staying there,they should be able too similar homes and or units in your area,give you a general idea of your bills with those providers...
it depends on two things how much you use and the installment you can get on a budget payment plan you would only pay so much a month to avoid discontinued services.
Good luck
ladies, figure 400...hundred bucks each...