I think that's right.

My wife is a practical, pragmatic person. But she wanted a diamond ring. She felt sheepish about wanting one.

The expense wasn't the appeal, and she's never been interested in signaling consumer goods otherwise like clothes, purses, fashion, jewelry, cars etc. If I had gotten a rarer, more expensive stone that was not a diamond, she would not have liked it as much. The cultural element of the diamond ring was a big part of the appeal.