In the literature on the Moral Limits of the Markets, Kant’s moral philosophy is often employed to assess the amoral or immoral nature of the commercial sphere. Markets and morality are antipodes since the instrumentality of market transactions excludes or undermines moral values. The kingdom of ends, where everything has either a price or a dignity, closes the door to market logic. The present paper challenges this view, which is also endorsed by business ethics authors advocating for Moral Purism. I will show that Kant imagined a market within the Kingdom of Ends where everyone pursues their own aims while assisting others in pursuing theirs. This model, built on the universalization of the maxim of mutual assistance and the duty of honoring the spirit of mutually beneficial contracts, can be employed to judge the morality of real (empirical) market transactions.