Ok, I haven't read any of the other responses as i don't need to. I've been married twice so I know what i'm doing. I'll keep this brief.
1. Too many guys get hung up on trying to get the perfect ring. Don't.
2.. Unless you're marrying another guy, as a man, you know nothing about jewelry. Nothing. Don't pretend you do. Don't try to find that little jeweler to "design" the ring. You're blowing, what, $10K+ on this? Would you spend this sort of money on anything else for another person without knowing anything about it? The girlfriend cum fiancee will be so happy to see you get down on one knee and she won't even really look at the ring at the time. She will say its beautiful. But chances are you will fuck it up, and she will secretly dislike it and whine to her friends about it.
3. So, knowing the above, do what I did (the 2nd time i got married as i'd learned from the first time). Firstly, buy a cheap ring from Michael Hill or wherever at one of their half price sales. Don't spend more than a few hundred. Fuck, you could even buy a fake diamond for a similar price as well (most women are usually just a clueless as blokes when looking at gemstones at first glance anyway). Lets call this ring "the practice ring". (Mrs CD actually got hers later adjusted by a jeweler friend and she still wears it occasionally on her other hand).
5. Propose. Congratulations. Make the situation romantic etc and the ring itself will almost be a sideshow. Then explain to the fiancee that you now want her to go ahead and get the ring of her dreams because you love her and she deserves it.
4. Let her take over from there. She will be so excited going to the jewelers with her mum or sister of BFF or whatever. She will now get the ring she really wants and is going to hopefully wear for a long time. its a win for you as, apart from paying for it, your job is done. if by any chance she is not happy with the end result, you are completely blameless. My wife's ring was eventually done by the Chinese jewelry place in Thailand who has been doing stuff for her family since they fled the revolution (which scored me even more brownie points with my MIL). It cost more than my car, and is beautiful. How the hell would I have been able to match that?
Thank you for coming to my TED Talk.
