I'm so confident that I am right (or that you are wrong) that I'm willing to bet on it. Oh, with your GPA, you're definitely going to be named valedictorian—I'd bet money on it.See also: bet, money
I'd bet money (on it).
Fig. I am certain. Charlie: Do you think Joe's planning to sell his house? Tom: I'd bet money on it.I'd bet money that Jane will get that job.See also: bet, money