I'll admit, I do want a diamond. However, I wouldn't mind if it's small. I would think to myself "if he can't afford to get me a diamond, then could he afford a family?"
You know how guys say it's biological for them to be attracted to certain features in a woman (symmetrical faces, attractive body, long hair etc.) ...it's the same for women. But we look at different things like status, financial means, height. We want to feel safe with them. I'm not saying we're gold diggers, but I would say most women want a man that will be a good provider. The ring is one of the first confirmations that he can.
I wanted to add that I read somewhere that the more money spent on a wedding, the higher the chance it will end in divorce. I don't see the big fuss in a huge wedding. I would rather have my small (or big one...you never know right?
) diamond that I can forever keep, instead of a big expensive party.