To the best of my knowledge, EMs still give couples wedding rings when performing a wedding so its value takes a hit from that. It also has two names on it so that unfortunately has a tendency to not be as attractive to collectors because its not a neutral wearable.
I'd estimate a value of 5m, maybe 10m if you're lucky. Now my suggestion, would be to try and find out who these folks were if possible. If you can somehow do that, than you might be able to track down one of them who lost it or close friends in game who'd pay more for it as a memory. You might be able to sell it for more based on the historical value in game if one of them was particularly well know.
Hope that helps.