I take it you mean monetary cost? In the UK I can expect to buy Roaccutane (the UK equivalent) for about £23 per week. That's based on me taking 20 week's worth of capsules at the 60mg dosage for my weigth (70kg). Basically, it vaires since they work out how much you'll need according to your weight and the severity of your acne. And, of course, the figure I quoted was in pounds sterling.