Is "can" in this sentence being used to imply the possibility of something? What is the nuance of using "can" here?
Yes, "can" in this sentence indicates possibility. In this case, it implies the possibility or the likelihood of non-white amputees having to spend more for a prothesis. So "can" in this sentence not only indicates possibility, but also probability. Ex: You can save hundreds of dollars on this insurance. Ex: Eating too much sugar can make you sick.