By the way congrats SLM, your ring is beautiful! You will LOVE wedding planning. I did, at least!
I agree with cheaper rings not always lasting. I know several people who's diamonds fell out, settings bent, prongs broke, and they weren't even that cheap. It's not that uncommon. Then you end up having to replace it (and spend again). I am not saying you need a huge ring at all, just quality, especially in the setting and the jeweler. You do want it to last. You wear it everyday and it takes a beating. I even take mine off when I get home each day (somedays it's never put on) and it still gets banged around.
Also, it can potentially become a family heirloom if you'd want. My father used his mom's diamond for my ex-step-mother and the setting was made into a ring for my 18th b-day (the ONLY piece of jewelry I wore until it was stolen 11 years later

). My husband made his grandmother's diamond into a necklace for his niece. So it is an investment of sorts. It becomes part of your assets as well.
I see many people suggest trading up later on. As I said in another post,
if you can (of course, depending on circumstances) "splurge" slightly now, or can wait a little to, do it. I would never want to trade up or get another ring after I got one (that's just me, very sentimental). A few girls I know wouldn't either, some would love to! So guys, know your girls' feelings on this before you maybe take that route.
Just a random comment, I don't think wanting a nice ring or having one that's a carat or two, means you are materialistic or need a giant rock to express your love. It seems like many on here feel that way or jumped to that conclusion. That's the impression I get from some posts at least ("size queen, wasting money, etc.") and that's not true for lots of people, imo. At least those I know. Sorry, I don't know why I felt the need to add this, just on my mind.