The worker is accosted by a widow, who asks him to "bargain with me." They agree on a wage, then negotiate where he will sleep. He turns down a place with the chap and the maid; she offers herself. Learning that her husband is dead, he agrees to marry
In plot, this is identical with "Tam Buie (Tam Bo, Magherafelt Hiring Fair)," but the form of the latter resembles nothing so much as "My Good Old Man," while "Bargain With Me" -- though it has a similar sung-and-spoken mechanism, seems to have some inspiration from "Billy Boy."
It seems to me best to keep "Tom Buie" and "Bargain With Me" separate, while noting their extreme similarity. Roud of course lumps them. - RBW