when Vanguard and Blackrock are the top shareholders of both Nvidia and AMD, of course this would happen

Nvidia, AMD and Intel discovered that they can abuse their oligopol to sell high end hardware (GPUs, CPUs etc.) for prices hardly related to manufacturing costs but mostly related to the professional buyers' increased income generation by using the hardware. Besides, there are a number of hipsters paying any amount to brag having the best consumer-labelled product. A few consumers or streamers suffer from their desire to run current high end applications, such as AAA games or the most demanding video editing with highest settings, while softwares are poorly optimised and some hardware aspects, such as VRAM (or Apple: storage), are gimped on below-high-end (or Apple: above base model) hardware.

Who are these people with unlimited amounts of money. The high end gpu was like 700 or 800 for the 1080ti. Now it's more than doubled in price.

Australian prices are a total rip-off, $300AU will probably only mean a $100US price rise.