My husband proposed to me with a ring he picked out. 17 years later, I can say it is not the ring I would have picked out for myself. I have always been a sterling silver girl, and my engagement ring was gold. But there was no way I was going to turn him down because of a ring. As someone mentioned before, you marry the person, not the ring. I have been wearing all sterling jewelry, plus my gold ring ever since. About a month ago, I was talking with some girl friends, and found that I could plate my ring to be silver. Call me ECSTATIC!! But it was still kind of hard to bring up the subject - didn't want to seem ungrateful for what I have. But hubs was like, sure!! And then he said something that completely surprised me. He said it was probably about time to upgrade our rings to something a little more substantial. Hit me like a ton of bricks!! I don't necessarily want to upgrade my ring, but now that we are not 19 years old, we can afford better/different/what we want.
So the point is: if you are really sure about what she wants, GO FOR IT!! If you're not sure, then you can still go for it, and she'll still love you the same. And keep it simple now, so that you can have something to build to (if so desired) in the future. I can't tell you how much I've changed over the last 17 years. I wish you both the best - there aren't many marriages lasting these days!!
Oh, and yes, Happy Wife = Happy Life.
TBM