My wife said The Donald said this. As in Mr. Donald Trump. I didn't notice where he said this or that this is one of his trademark saying (sorry Mr. Trump). Maybe in one of his books which we have quite a few in the house, which I still have to find the time to read or maybe it is one of the few television interview that he is famous for.
As a businessman, I think this is one of the best advice you can get. Always ask what you can get if you do something. You can then calculate all the cost and then calculate the return. If the return is more, why ask anymore, just do it. If it is not, you better think twice or don't do it at all.
However, The Donald took it to another step when he also brings this to his personal life especially his marriage. All the jokes about rich men and marriage comes from him. Per-nuptial agreements are famous for him. I bet there's a lot of family lawyers who made tonnes of money thanks to him.
I actually have this tendency once when I was still single. Going out with girls who can advance my career. And, to tell you the truth, my wife wins hands down in this department...