Just because the hamburger is undoubtedly a signature fast food item, doesn't mean that you can't treat yourself and empty your pockets by tasting one of the world's most expensive burgers. For those with money to blow, there are some very pricey-and hopefully very tasty-burgers available, and you'll never guess who has recently come out with the most expensive burger in the world

.The Fleurburger#4 FleurBurger 5000 - around $75Are you willing to part with $5,000 for one, though? Renowned chef Hubert Keller thinks you might be. His FleurBurger 5000 is available at Fleur de Lys, a traditional French restaurant located in Las Vegas' Mandalay Bay Resort and Casino. They'll even mail a certificate to your home just to prove that you ate the world's most expensive hamburger.So how do you rationalize a five grand price tag for a hamburger? Well, you could start with the fact that the burger itself is made of Kobe beef. You could, then, move on to the foie gras-that's duck or goose liver-and black truffles with which the burger is topped. You could even point out that the hamburger is served on a brioche truffle bun and is garnished with a sauce containing even more truffles. Then again, it could be the bottle of Chateau Pétrus 1990 and Ichendorf Brunello stemware, specially imported from Italy, which you get to take home. Yeah, that might be it.Of course, if you actually want the world's most expensive burger, rather than the most expensive burger-and-wine combo, then you may have to look elsewhere. The Fleurburger can be ordered by itself for a mere $75

.#3 The Tri-Beef Burger - $125The Tri-Beef BurgerOne expensive burger was created in 2006 at the Old Homestead Steakhouse in Boca Raton, Florida. Called the Tri-Beef Burger, this is made of a blend of three different kinds of beef-American Prime, Japanese Wagyu and Argentine beef. The hamburger is served with signature Chipotle ketchup made with truffles and champagne. As if the beef isn't reason enough to purchase this expensive burger, the restaurant's owners donate $10 of every sale of the $125 burger to the Make-A-Wish Foundation

.#2 The Richard Nouveau Burger $175The Richard NouveauThe Richard Nouveau is a more recent entry into the most expensive burger hall of fame. Named after the fictional writer of PocketChange, an online newsletter about NYC's most expensive offerings, the Richard Nouveau is available at the Wall Street Burger Shoppe. The ten-ounce Kobe beef burger is topped with black truffles, seared foie gras, aged Gruyere cheese, wild mushrooms and flakes of gold leaf. Like the Fleurburger, it's also served on a brioche bun. The burger was created when PocketChange's Jeremy Abelson suggested that the Burger Shoppe's co-owner, Heather Tierney, outdo the $120 burger offered by another local eatery. With the Richard Nouveau's $175 price tag, they've clearly done so

.#1 Burger King's The Burger - about $186The BurgerHot on the heels of Wall Street Burger, surprisingly enough, is Burger King. Yes, this monolithic fast food giant has decided to live up to its name by producing the world's most expensive burger. Called simply "The Burger," this costly hamburger is available only at a West London branch of the restaurant. Luckily for those who'll be taking their private jets to Burger King for lunch, The Burger can be pre-ordered by phone so that you needn't wait.The most expensive hamburger is made, as usual, with Wagyu beef. It is also decked with white truffles, onion tempura prepared in Cristal champagne and some of Italy's finest Pata Negra prosciutto. All of this is presented in an Iranian saffron and truffle bun. The Burger is priced at £95 (about $186 US). While it has been derided as a cheap marketing stunt, proceeds from The Burger will benefit a local charity, Help A London Child. All things considered, I'd say it's at least an expensive marketing stunt.