There are a great many couples in my social circle who eschewed the diamond ring. They have meaningful, and expensive alternative rings, but not diamonds. We don't have diamonds either.

My only point is that not ALL women are about making other women feel inadequate. Or showing off their diamonds. Many are actually just as disgusted as men are about it. And they prefer men who have that conscious, and will put some thought into an alternative.

However... Your last suggestion, I grant you, has merit.