That is a very good question. The answer is no: an oven consumes more electricity to maintain its temperature at 400 °F than at 200 °F. Once the set temperature is reached, the heating elements are turned off and then turned back on at regular intervals, in order to maintain the temperature. The higher the temperature, the more often the elements will go on. Another impacting factor is the room temperature in the kitchen. It the temperature in the kitchen is 21 °C, the stove will consume about 2.5 times as much electricity to maintain the oven at 400 °F as it would to maintain it at 200 °F.