Effective altruists aim to do the most good that they can do with the resources available to them, without causing themselves or their dependents significant harm thereby. The argument presented in this paper demonstrates that there are no morally relevant dissimilarities between living kidney donation and living kidney selling for effective altruistic reasons. Thus, since the former is allowed, the latter ought to be allowed as well. And, there are important moral differences between living kidney selling for effective altruistic reasons and other reasons for kidney vending (e.g., for personal financial gain), such that standard objections against markets in human kidneys do not attach to those markets designed around principles of effective altruism. The reasonable conclusion to draw from this is that eligible effective altruist kidney donors ought to be allowed to sell (one of) their kidneys to others in need, if they so desire. Because of this, law and policy ought to be changed to allow for this exceptional case: current laws that ban kidney selling for everyone, irrespective of their reason for selling, are unjustified.