The cost is only everything she has.
As you know, we're fascinated by pseudonyms. Murder Is the Pay-Off came from the typewriter of Leslie Ford, whose real name was Zenith Jones Brown. We can't imagine why she decided not to publish this under her own name. After reading it, we think the book must represent something close to the zenith of her authorial output. It's an interesting and well written mystery originally published in 1951, with this Dell edition coming in 1954 fronted by Carl Bobertz cover art. The novel is set in the fictional New York City satellite burg of Smithville, where the murder of a slot machine magnate turns the close knit community upside down.
A lot happens in the book (in that upper crust, smalltown sort of way), but at its center is ambitious and egotistical Connie Maynard, whose behavior makes the police suspect her of being the killer, though she isn't. She has her reasons for keeping quiet. She's ostensibly the secondary villain in the narrative, but we liked her. It was easy to do because every major character is flawed. While Connie is trying to steal someone's husband and refuses to reveal her innocence, her rival Janey Blake is a chronic gambler who's lost her and her husband's life savings, and Gus Black, the hero of sorts, is work-driven, neglectful of Janey, and sometimes oblivious.
The identity of the killer is strongly hinted at about halfway through the book, at which point the multi-pov narrative expands to include that person's interior monologues. It's precise and highly intelligent work from Ford. In addition, there are interesting proto-feminist themes, specifically Janey dealing with presumptions of stupidity from the men around her when she's really one of the smartest people in the book, and Connie encountering sexism in her professional life. At one point Gus—the hero, remember—even tells Connie, “I wouldn't work for a dame anyway.” Literary protagonists aren't usually chauvinists to such an overt degree, even in 1951. Well, we'll work to find more Ford. We want to read her again.