About cultural/"cultural" differences
This thread actually got me to register here on the forums
Anyway, I'm from Finland, and here the whole ring-thing is quite different.
First of, the engagement ring itself is most often just a plain golden ring. Or plain titanium ring, like a couple me and my wife know.
And they (because it's for both of them at the same time) usually bought by the one making the proposal (even to this day it's more often than not the man).
Our's were about 500 for the pair of them. I could've bought more expensive ones, but they would've been wider and thus not so elegant. (My wife fully approved my decision and sense of style

)
The actual wedding ring here in Finland is the "one with rocks". But nowadays it's quite often selected by the bride herself. Again, there might have been more expensive ones my wife would've liked, but she was very satisfied with one costing about 1000. And actually payed a quarter of it herself! The one thing she WAS concerned was that we would get a certificate for the diamonds not being blood diamonds. (I wouldn't have paid for blood diamonds either...) Also it's getting more and more customary for the fiancee to have a second ring too, but I haven't seen any men having the double ring combination, which is the way that women wear the engagement and wedding rings. (And it's on their left hand...)
And about the wedding itself. We saved and payed for it ourselves. It's not yet uncommon for the parents of the bride to pay for it, but quite often it's payed by the couple by themselves if they aren't that young and have jobs. (As we both had and still have...) And it's in no way unheard of to have the folks of the fiancee to pay for the wedding. I know a couple of that sort. The reason was obvious: the parents of the fiancee were clearly better of than the other parents.
Don't know if this post has any real value or usefulness to anyone, but just an interesting side note about small differences in cultures, that are superficially the same.