Oxygen sensor price which is 3 times expensive than the new one the

They always have my Audi RS4 parts but they're more expensive than the new one, I wanted an oxygen.sensor which they said it's R3000, I checked online it is R875, including the shipment it is still less than R1000. Even a fog light grill they sell it for R1000. And it's cheaper online. They're too expensive for me.