If marriage really is that important to you and you've told him this, then maybe it's time to think about what both of you want.
Where do you want to be in 5 years time? Ask him where he sees himself in 5 years. Explain to him why marriage is important to you. Ask him to explain as to why he's opposed to the idea.
And take a while to think why the "grand gesture" is so important to you. Because grand gesture isn't the thing that glues people together or what gives them security: open and honest communication does that a lot better.
