You’ve rehearsed the spiel in your head. Spent too much time worrying about what they’ll say. Wonder what your options are if they turn you down. You’ve put it off and put it off. It’s getting closer to the big night and you’re running out of time. You can just go ahead and ask them, right? Not really. Promposals are kind of a big deal. A report released by Visa Inc. indicated that promposal spending in the United States averaged $324 per household last year. As graduates-to-be find increasingly elaborate ways to pop the question, simple promposals are falling by the wayside in favour of grander gestures ranging from the…