I usually don't comment on the people who comes here asking ques

I just can't help wondering where you received your education. do you really think marriage is a contract? did you pay her to get married with you?

that said, if you do have such a contract, it might even be enforceable, if the contract meet certain conditions. usually it must be in writing, and you must give her full disclosure about your conditions, and she must had reasonable opportunity for an independent counsel before she consents to the contract. Otherwise, it is unenforceable.