End of modeling, please. In order to be able to figure out what people want, buyers and sellers have to talk. That doesn't mean they have to talk during the transaction. One of the open problems is how to do exactly this communication in the face of total anonymity at the point of transaction. There are some answers in an area of economics called mechanism design.
Mechanism design is an outgrowth of game theory.
Let's do an example. But I don't care what their worth is, just whether or not it's sufficient for the transaction. Back to the example. Suppose a seller can create and sell one of three things. The seller can do one, but not all at once.