"would tend to reconsider any long term relationship with such a person"

Are you arguing that anyone who would accept and display a precious gem is ineligible for marriage? More so if it is larger, but not if more expensive? The post you are replying to presents a plausible social economy of the tradition. What is your point?

Are you arguing that anyone who would accept and display a precious gem is ineligible for marriage?

No. My point is that anyone who conditions marriage on the size or cost of a diamond is ineligible to marry me.

My wife accepted my marriage proposal without a ring. One was added later --- after other more urgent finances were covered and reassuring her that it would be modest and not overly wasteful.

In other words, this was done strictly because I wanted to --- not as a pre-condition for her acceptance. She says doing it this way was more meaningful.