Yi bai kuai is a common everyday phrase in Mandarin, literally referring to one hundred units of currency in casual speech. Short spoken price clips like this circulate online as standalone reaction sounds because they are easy to understand even out of context and easy to reuse. Creators place the audio over unrelated footage to turn an ordinary purchase, trade, or negotiation into a joke about cost. Its continued use comes from that flexibility, as the same brief amount can sound generous, cheap, or absurd depending on the scene.