This can be a very tricky question. My current one-bedroom apartment runs me between 60-$120 a month. Lower costs spring and fall, higher in August and January. My former apartment (larger) had no insulation in the ceiling (flat roof building) and basically could not be heated over about 62 degrees and still ran me $200+. Neither could it be cooled to 85° for less than that. All I can say is: watch (be wary of) old buildings, and be wary of recently rehabbed buildings. My building was a converted shoe factory. A lot to love, but essentially no climate control.