Somehow I re-read your post like 4 times and still thought you were saying "get married AND your money back", not "get married or your money back".

So here I am, downvoting my own posts.

I will say that your idea is trivially gamed. What startup is going to keep the legal staff on retainer to sue every person who "breaks up" with their partner, gets their refund check, and uses it to buy an engagement ring?