This article explores how the thirteenth-century verse Vida de María Egipciaca portrays the sins, conversion, and spectacular penance of Mary of Egypt in terms of her rejection of and eventual entrance into orthodox economies. As I argue, hagiographic legends about prostitutes have economic subtexts and the Vida offers paradoxical visions of prostitution both as a foil and as an analogue for the financial metaphors that undergird the very economy of salvation. In the Vida prostitution, as practiced by the repentant María, not only represents sexual depravity, but also a move from economic indifference and the unregulated distribution of sexual activities to a consciousness of just prices and exchange values. The poem thus offers a striking medieval articulation of Christian salvation economy, relating the salvation economy to notions of women’s value as objects of exchange. In so doing, the Vida also interlaces the context of thirteenth-century Mediterranean economic culture with its poetics.