Your last paragraph, as well as Lorin's answer, is correct.
You should always think about the difference in cash flow between a world in which you take the project and a world in which you do not. In this later world, Maria would have more cash flow because she will rent out the apartment (or live in it and save the rental of her own apartment)
Best
You should always think about the difference in cash flow between a world in which you take the project and a world in which you do not. In this later world, Maria would have more cash flow because she will rent out the apartment (or live in it and save the rental of her own apartment)
Best