That's a framing issue. "Should we spend $X of our now common budget on a ring, or spend $Y < $X on a ring and buy a nicer car/pay out the house faster/add som

That's a framing issue. "Should we spend $X of our now common budget on a ring, or spend $Y < $X on a ring and buy a nicer car/pay out the house faster/add some more to the kids college fund?" If she says "the ring" to that, consider a replacement.