Before I took my first bite of the FleurBurger 5000, I was one of those people who thought paying $5,000 for a hamburger was both obscene and insane.

After all, a top-of-the-line burger from Shake Shack or In-N-Out costs less than $10 — and they don't get much better than that.

But then I found myself in the kitchen of Fleur, Chef Hubert Keller's restaurant at the Mandalay Bay in Las Vegas. I watched Keller quickly sear a patty of Wagyu beef ($100 a pound) and douse it over and over again with rich butter, sealing in the flavor and the juice.

Then I watched him slice and sear a few slabs of prime foie gras ($45 a pound), and combine the duck fat with more butter to sautee a mound of sliced black truffles ($1,500 a pound). After that, Keller carefully layered the three ingredients onto a freshly baked brioche bun.

The top ingredient (and the main reason for its price) was poured rather than cooked: A bottle of 1995 Petrus. The bottle, which can often sell for more than $5,000 in restaurants, comes with the burger as the perfect pairing.

With wine in hand, I lifted the earthy, oozing Fleur burger to my mouth and took my first bite. And for the first time ever on "Secret Lives of the Super Rich," I was completely at a loss for words. My exact quote, on camera, was, "Oh! Wow. Oh. My. God."

Would I pay $5,000 for a Fleur burger? Absolutely — if I were a billionaire.

And others certainly agree. Hubert has already sold 28.

Watch "Secret Lives of the Super Rich" on Thursdays at 10 p.m. ET/PT.