I have a gaming PC that I bought for 2000 EUR pc that I built for entertainment and some work. 4000 EUR is so much out there that I cannot imagine who is buying it with his own money
My Apple //e setup cost around $3500 in 1986.
My Mac LCII setup was $4K in 1992.
There are enough people in the world who will drop $3500 on the Vision Pro without blinking for Apple to sell all it can make.
People buy skiing equipment for 2000€ Euros just to go skiing a few times a year. They buy mountain bikes or road bikes for 5000€. They buy brake upgrades on their sports car for 7000€.
I think Apple will easily find a few people willing to spend 4000€ on a toy.
Whether the market will be big enough for 3rd party developers to be sustainable is another question.
Top designers for Ferrari? Famous architects working on buildings costs tens of millions? Other expensive people like that I can see it.