Yes, we got used 1920s (or 40s, I forget which) diamond matching (engagement/wedding) rings from a local jewellery market for ~5% of the cost of the equivalent

Yes, we got used 1920s (or 40s, I forget which) diamond matching (engagement/wedding) rings from a local jewellery market for ~5% of the cost of the equivalent spec ring if it were new. It was in immaculate condition and my wife adores them still 15 years later.