When you go to a business and say you can buy a widget for $1000, or for $500, and they both do the same thing, the business will choose the cheaper one.
Okay, but that's not what's happening. What's happening is one business/industry controls to the supply for that widget, and that business only sells the $1,000 one, because they invested $1B to ensure that was the only option. Because that business does not offer the $500 option, and does not care to.