If you think truffles are expensive try Matsutake, a Mycorrhizal Mushroom that sprouts life for a few weeks per year and are hard to find. This is $350 for a single mushroom and forget the weight because it is 97% water. Prices per kilo can easily be in excess of $4000/kilo.
The surface is smooth and dry, the stem short and broad. With age, the cap and stem develop rusty stains where bruised. But it is the odor that identifies this mushroom. It is very clean, like no other foodstuff. Japanese chefs treasure this delicacy, and their preparations reveal how to bring out its strong fragrance and individual flavor.