Earlier quoted context omitted.
Digital tulips, only tulip farming didn't consume the same amount of electricity as a small, South American country every year.
Things only have value because we agree they do. The US Dollar is backed by the full faith and trust in the government. "Faith and trust" is as much a digital tulip.
Second, you have natural scarcity: truffles are not commonly available. How much you want to eat them may put a ceiling on the price, but again there is also a floor below which no amount of energy would bring you more truffles.