Once found they are sold through a cooperative, as a chef I went "hunting " in both Italy for the white Alba truffles,and in France for the black summer one, they are taken to a wholesaler or to a processing centre, Harrods the one time I was in there in the late 1990's had a display, and a guard to keep people from nicking them. It is a hit and miss situation some days they find 4-6 other days more some days none, and now they use dogs, as pigs whether they be sows or hogs/boars have a tendency to want to eat the truffles, and they leave a nasty scar when bitten.