Yes and No
If you fail, you only need to fix the questions that you failed. For the first fix there is no cost. Usually for the second fix there is also no cost unless it is obvious that you are just throwing in guesses to see what sticks. Honest and diligent attempts at the exam are appreciated. If you take the time to understand the concept and that is obvious then we will not charge you. Keep in mind that it is a real person's time that is grading the exam and we want him to feel as though he is being valued.