What is the rarest and most expensive mushroom?

It’s the truffle, is collected by excavation. The black truffle of Périgord can reach 1000 euros per kilo in certain years, it remains however more accessible than the white truffle of Piedmont. The price of the latter can sometimes exceed the understanding. For example in 2004, two white truffles of 1050g and 852g were sold about 41 000 and 52 000 dollars.