How would it affect the world economy if other players entered the oil market

The big elefant in the room "the war on terror" is that it is all about oil and gas. As we know Argentinia tried to enter the oil and gas game in the capian sea and by extension Afghanistan, seen as how between Russia and Iran its the only feasible route to get the stuff out.

Now some people say its all about making big oil corporations richer. How would it affect the average German the average American if other players entered the game? Is it really just about making the rich richer, or would it adversly affect the average joe in the US and EU as well, if other players entered the market?

The more who buy oil, the more the price goes up. However, if you look at certain parts of the world, gasoline costs hundreds of times less than it does in other parts. So it's just a bunch of price gauging, price fixing, and the rich people ripping off the average human.