DUI Lawyer Average Cost. The average cost of a DUI is $7,000 to $10,000. As far as the cost of a DUI attorney, that depends on the severity of your charges and how vigorously they are defended, but in general you can expect to pay somewhere around $ 100 to $400 per hour.s far as the cost of a DUI attorney, that depends on the severity of your charges and how vigorously they are defended, but in general you can expect to pay somewhere around $ 100 to $400 per hour.