In this instance, I prefer the obvious and simplest answer: As little as possible. You cannot put a price on love. True. But you can and should spend as little as possible on a beautiful engagement ring that you will love and that will symbolize your love forever. $ do NOT = love. Find the ring you love the most that is priced the least. A ring to love does not and should not cost more than you are happy to pay. It doesn’t have to be a diamond ring, but it certainly might be. It's an engagement ring because you propose with it. Think about it, talk about it, feel it. Find something you love.