I didn't pay for here engagement or her wedding ring, both belonged to my mother. Here wedding ring belonged to my grandmother, we recently had it appraised and found out it was worth about $8k. I can't imagine what it cost 60 years ago.
Regardless, we both win. She got her diamonds, I didn't have to pay for them. Some of her friends have more expensive rings, but they all agree that my wife's ring is the most beautiful. The fact that it is a family piece means so much more than something new.