(Image credit: Liz Steger/Serendipity3)

Nothing is more fulfilling in the summertime than a juicy burger.  In honor of National Hamburger month, we've rounded up some of the priciest burgers in the country.  While you might be used to spending no more than $10 on a patty, these restaurants take this favorite American food to a whole new level.

1.  The $666  Douche Burger at 666 Burger is a Kobe beef patty stuffed with foie gras and wrapped in gold leaf. Caviar, lobster and truffles top the burger.  Gruyere cheese is melted on top with champagne steam and the burger is slathered with BBQ sauce made using Kopi Luwak coffee.

2.  Serendipity 3's Japanese Wagyu beef burger infused with truffle butter, Le Burger Extravagant, costs $295.  The burger is seasoned with smoked Pacific sea salt, topped with hand-formed cheddar cheese, black truffles and a fried quail egg.  It's sandwiched on a buttered white-truffle Campagna roll and topped with caviar and a diamond-encrusted toothpick.

3.  At DB Bistro Moderne in New York City, $125 gets you their Double Truffle burger which is only available during the season in the fall.  The burger is stuffed with foie gras, root vegetables, black truffle and red wine braised short ribs.  Fresh black truffles are shaved on top.  It is served on a toasted poppy seed and parmesan bun with fries.

4.  In Pensacola, Fla., McGuire's Grand Burger is made of filet mignon and costs $100.   It's served with a side of caviar and a grand magnum of Moet champagne.