This phrase is used when you want to emphasize that something will or will not happen in your opinion. However it is often used in a jokey or pessimistic manner. It is basically a substitute for 'I bet that' without the promise to pay out money due to the fact that money is the subject.
Money says she pulls him before the morning.
Money says the hearsebreaks down.
1. When one's goal is to fuck as many women and make as much money as possible, while simultaneously getting as fucked up as possible, on any hard street drug.