Air conditioners consume a lot more electricity than an electric fan. A central air conditioner can consume up to 3,000 kwh of electricity per hour.
That can cost your 30 cents per hour to run. 30 cents an hour x 20 hours = $6.00
Central air conditioners can cost as much as $6.00 per day to run x that by 30 days =$180.00 a month.
That's quite a bit of money if you don't have much money to begin with.
A fan will use around $7.00 per month. So yes it's much cheaper to use a fan instead of an air conditioner.