Should a box cost $90? Well, if a phone can cost $500 and be socially acceptable, then yes - an expensive, fancy box like this is completely normal.
It was designed by packaging designer Andrew Zo for the company Clifton, and it's described as "a slimline engagement ring box that slides into your pocket with less resistance than a wallet. When you open the Clifton, the ring doesn’t just appear. It pirouettes into position thanks to a pop-up mechanism intended to present the ring like a blooming flower."
Ummmm, this is incredible? And even if you're not proud of giving whatever ring is inside - anybody should and better be wowed by this damn box. (And as a small sidenote: anyone who has ever complained about the details on a ring/GIFT that someone else has given you, you can go right to hell. It's the gesture that's kind! Not the damn object!)
I wish one of my hobbies somehow included giving rings to people 'cause I would be all over this box. Man. So cool.