I had to fight my Chinese wife's tooth and nail not to play in that shame game "but everyone else has a huge diamond ring". My god, get it yourself, it's just a ring, I won't do like some friends who borrow on 5 years to buy one so big the girl is scared to wear it and put it in a safe...
I bought her a small 300 euros one, she found it almost insulting but after a month, stopped wearing it "because it's a bit heavy" and "it's just a ring, it's true it doesn't really matter". 5 years later, we're still married with a child and she wouldn't even remember where she put the "diamond".
But it's still better not to buy into the scam in the first place.
I'm not American, and Dutch culture has no special preference for diamond rings. (Just plain gold wedding rings.) Or at least didn't; it wouldn't surprise me if this scam has also been crossing the pond like so many other questionable ideas.