A third party should not be able to profit at the expense of both buyer and seller without adding some service to them. The seller should be able to sell for w

A third party should not be able to profit at the expense of both buyer and seller without adding some service to them. The seller should be able to sell for whatever they want, and if they know Disney is selling and they raise their price accordingly, then so be it. I'm assuming you're drawing an analogy between this scenario and trading on the stock market. The difference with the market these types of deals are expected--people with different levels of understanding will make trades in their own interest.