Three rules follow from the biology. First, harvest at the button or egg stage, before the volva breaks. The volva is the skin that wraps the young mushroom like an egg shell. Once it tears and the cap opens, the mushroom turns fibrous and the price drops.
Second, this mushroom cannot go into a fridge. At 4 °C it undergoes autolysis, meaning its own enzymes digest it into a wet mess. DMR gives 10 to 15 °C for about 3 days, and says most is sold on the day of harvest.