No standard course of treatment is there and the number of sessions you will need greatly depends on your health condition and current symptoms. Also, the severity of your condition and how your condition improves with the treatment makes a lot of difference.
Your health practitioner will assess your improvement regularly throughout the treatment to give you an idea about the length of treatment you will need. Some herbs may take longer to have an effect on the body, so you might not see the progress in your condition for weeks or months. Consider this information when thinking about the cost of your treatment.