My wife picked up a cheap bottle of what claimed to be truffle oil at a chain grocery store in Herculaneum (that's in Europe) last year. On inspection, it was actually a bottle of cheap vegetable oil with a slice of some other kind of mushroom in it and a hint of trufflesque flavoring. Maybe somewhere in the fine print it said what the flavoring actually was, but the rest of the bottle, from the "TARTUFO!" label on the front to the fake truffle chunk inside, was a blatant con.