Unfortunately the real price is what someone is willing to pay. The same people that pay 2x as much for the same McDonald's via Uber Eats are the ones probably paying 2x as much for soap on Amazon for the "convenience" (laziness) factor.
Sure, if they can sell as many as they want for twice the regular price,it makes Amazon less useful for me, but that’s up to them. My objection is mainly the sizable constant fluctuations.