Actually the medication comes in other brands known as Acnotin, Nimegen as well, and many aesthetic GPs and dermatologists can prescribe the medication to you.
It should cost anywhere between $60-90 / month for the above mentioned brands. For Accutane, it would cost much more as it is the branded drug.
Do take note that pre-treatment blood tests would need to be done and adequate blood-test monitoring thereafter as well.