SUBREDDIT: r/relationships
TITLE: Me 35/M with my 33/F - Want to propose on our overseas trip and buy the ring there -- how can I do this?
POST: So my girlfriend and I are pretty serious, and we've talked about marriage and we're both on basically the same page. I'm really ready to take the plunge and propose!

I got her a trip to Paris, France for her birthday, and we'll be there at the end of the year. I think it would be a wonderfully romantic place to pop the question, especially because we'll be there over new years (which has always been a really special night for us as a couple.) 

The thing is I think it would be awesome to buy an engagement ring in Paris, so she has an amazing reminder of our trip and the proposal. 

But then, what do I do about the ring for the proposal? I've heard people say propose with a walmart ring, and then shop with her to get the real one, but I'm worried that it would look non-committal to have a placeholder ring (like I'm trying to limit my losses if she says no.)

At the same time, I don't think I could propose without a ring, because that would feel even worse.

I also think trying to "sneak away" for a couple hours to buy a ring on the first couple days would be pretty suspicious/weird, as we have a pretty busy tour schedule planned.

So I guess how can I give my girlfriend and awesome proposal, AND an awesome ring while I'm overseas?

Has anyone been proposed to with a placeholder ring? Does it come off as cheap/insincere?
TL;DR: 
Is proposing with a placeholder ring ok if I'm going to buy a super-fancy one a day or two later while we're in Paris together?