Is this sentence grammatical and natural? Please suggest some other ways of saying this.

How desperate for money could someone be for them to talk like this?


Delete "for them." It isn't necessary. Additionally, you said "someone," which is singular, and then you used "them" to refer to "someone." It's a common way to speak, but it isn't really right. You want to avoid it especially in writing. Change it from "someone" to "people" or some other plural word. Then you can use "them." At any rate, you don't need that "for them" in the sentence.

How desperate for money could people be to talk like this?

Thanks for your informative suggestions.💖😇