Ok...but the point is that after they achieve the monopoly they can jack up the price to well over a thousand dollars without worrying about losing market share.
Basically, it's not a problem if you happen to be the best in computers. But it's a big no-no to try to force resellers into exclusive contracts and so on. (If you continue to just buy up newcomers to the market that's not a problem, after all investors can just keep funding new competitors and you have to waste money.)
But of course this is a very difficult problem at the intersection of economics, politics, law and sociology.