You have to consider the size of your apartment and the general climate. An average electric bill may be as low as $30 per month or as high as $100. Gas may cost, on average, anywhere from $40 to $150 and can fluctuate depending on the season.he average bill for each falls between $10 and $30 a month, although you may be billed at a flat rate for both that can cost between $20 and $60. Although many apartments have an apartment complex trash can in which you can deposit your garbage, you’re still likely to be billed for pickup.