My group and I ordered 3 Kobe beef burger with foie gras, total turned out to be around $200 because we ate wayyyy too much.
Foie Gras- ummm, not the best experience I've had. i drenched it in the burger sauce because I couldn't taste the scrumptiousness of the foie gras. I wouldn't recommend Burger Bar if you're solely here for that.
The nutella sandwich- which is essentially a chunk of nutella squeezed between two donuts and gelatin is a heart attack on a platter. Just make sure you exercise for the next 3 days so you don't die, because it's really yummy!