Over the weekend, a 4.16 pound white truffle—the so-called "World's Largest"—sold at a Sotheby's auction for $61,250 to a phone bidder in China. It was actually a bargain price for the over-sized fungus. This year's large crop, a result of abundant rain in Italy, has seen wholesale prices drop by 50 percent from two years ago.

To figure out a little bit about why truffles are so expensive, we talked to Vittorio Giordano, the Vice President and Truffle Guru at Urbani Truffles USA. First started in Italy in 1852, Urbani now sells to 68 different countries.

Urbani's white truffles, which are rarer and more expensive than the black truffle, still come from Italy. (They can also be found in Croatia, but lately the Italian crop has been sufficient.)

"Truffle is a wild product, it is a natural product. It is not something you can cultivate or control," Giordano explains. This unpredictability contributes to the extreme prices truffles can fetch. People have tried for generations, to no avail, to farm truffles. And while recent attempts in the U.S. and Australia to recreate truffle-conducive habitats by planting chestnut, oak, and hazelnut trees have shown modest success, the crop has been insubstantial and rarely are full truffles salvageable.

Instead, Urbani works with a network of 18,000 people to hunt for truffles around Italy. "A single truffle hunter with a dog can find a small amount—two ounces, three ounces, quarter of a pound—so we need a lot of people to make sure we are able to collect quantity we need," he says. All those employees only drive the price up further.

It used to be the case that pigs took the place of the dog in that picture. Female—and only female—pigs were the original truffle seekers; the truffles smell like testosterone to the lady swine, making them easy and eagerly sought out.

There is a problem with swine, however.

"Pigs eat truffles. They don’t want to give the product back," Giordano says. So, dogs were trained to put their noses to use for the cause and all they ask in return is a treat from their handler. (In fact, use of the pig to hunt truffles has been prohibited since 1985 because they damage the truffle beds in their zeal to get to the scent.)

Once the truffle is unearthed—and a portion of the precious find is put back into the ground to act as a spore and repopulate—there's the matter of getting the truffle to a plate. Truffles immediately begin losing water to evaporation as soon as they're dug up. To combat that, no expense is spared to get the truffle where it's going. 

"The truffle we deliver to the restaurants and distributors, less than 36 hours before were underground in Italy," Giordano says. And the cost to make that happen adds up. Black truffles, the more common variety, currently cost about $95 per ounce while white truffles top the charts at $168 per ounce. But the much more reasonably priced truffle butter is pretty delicious, too.