"People as a collective" don't have a price, people as individuals do. The market sets it at the maximum amount so that the product sells out.

The market IS the collective. An abstraction of individual choices into a broader trend.

If that number exceeds the number of products available, then yes, they do control the price. If there are 300 items left, the market price is the 300th-highest price that anyone is willing to pay. People who bid below that don't get one.

That isn't what market price is. Market price is the price for something ACROSS THE MARKET. If someone wants to pay $1 million for an old beat up Toyota, the market price for an old beat up Toyota doesn't become $1 million. You are confusing selling price for market price. Unless those 300 items represent the entire market that existed, the inflated rates paid on them are not market price. They are simply high selling prices. You are completely misunderstanding the terms you are trying to apply here.

There is no hivemind that sets prices. There are only individuals and their decisions.

Of course there is no hivemind that sets prices. You're the one who brought up a hivemind, not me.