What advantage have you made of his death ? or what advantage may yet be made of it ? Did you secure 35 the keys of his treasure-those no doubt were about him. What gold, what jewels, or what else of value have you brought me ?
This dialogue from Millwood to Barnwell is a perfect representation of the transactional, clinical lens with which she views their relationship. Her use of nouns such as “advantage” and “value” (which have deep monetary associations ) contrast with the deeply upset state of her so-called “lover” and so clearly indicate how she places personal gain above any pain felt by anyone else around her. This goal-oriented way of thinking is more reminscient of an exchange or business deal than of a functional relationship.
It becomes clear that this callous manner of thinking is something she carries with her throughout her life and not just in her relationship with Barnwell when at the end of ACT IV she expresses that, in her view, people go through life “devour[ing] or [being] devoured as they meet with others weaker or stronger than themselves." Here, her matter of fact tone contrasts with her use of the carnal verb “devour” and so further solidifies to the audience just how deep her tendency to view life as a mere series of emotionless exchanges runs.
Her callous, transactional way of thinking eventually drives her to being arrested without any sort of redemption in the audience’s eyes. This ties into the larger moral of the play by expressly showing how going through life like it’s a clinical business deal and rejecting your humanity has dire consequences for you and your character.