If 90% of the people think it is worth $1 and 10% think it is worth $1000 then it is worth $1000.
" If you don't like the price something is offered at, don't buy it." No it isn't that simple sadly. In this case it is tantamount to saying that if Apple doesn't like the price of the LCD displays it can simply stop making iPods. That is the point of collusion and monopolies (and collusion is simply another form of market monopolisation.) It is always a matter of squeezing the customer, without driving them out of business. There is a measure of brinkmanship. One has to be sure that one doesn't squeeze enough that the customer is tempted to do something dramatic - like setting up their own LCD plant. The large capital barrier to entry and ownership of patents can help here.
The issue with monopolies and collusion is that they distort the market. By making the market one sided. The ideal of the market is that competition exists. Without and the market fails. Protecting this ideal is a serious thing. Whilst individual companies love the idea of controlling a market, it isn't a market, essentially by definition, if they do.
Same with oil. Come winter people need to heat their houses. Disliking the high price of oil does not allow them to decide not to buy it. Eventually something gives - they move to another country - or another source of energy becomes cost effective. But the choice to simply walk away often does not exist. Commodity markets are an interesting middle step. In principle they should reflect a market driven price. Mostly they do. But it is possible to distort them, at least for a while. The Hunt brothers and their attempted cornering of the silver market is perhaps one of the best known. Cornering the market for oil is always going to be very hard. OPEC does not not control enough of the world's reserves to do so, and has traditionally had a very poor time controlling its own members.