Of course the driver is not exactly the same, Perlisten does of course everything to look different then a driver of just ~300 dollars. That's exactly the trick.
They would be stupid to buy "of the shelf" drivers, customized specs create extra profit because the end consumer doesn't have comparison material. It creates exactly the kind of myth that is needed for the highest possible selling price. Not that there is something wrong with it, but it's a known fact that the exact materials are not creating the price of an high end high performance speaker.
There is no reason to assume that Perlisten can do something better with the same cone material then the big established driver manufacturers can do after many years of research and production. There is no magic going on there, great performing drivers can be bought and are available in the market for all manufacturers.
But it's still a serious job of research to integrate them well for that reason prices of high end speakers can be justified. I don't believe that the DIY guys (besides subwoofers and other hardware such as amplifiers) can create the same performance in the end as passive speakers from Perlisten/Revel/Focal/Kef, I've not seen proof of this, there is always "something not as good", a missing waveguide, a resonating housing etc.etc. so the price can still be justified even while the prices are insane when you look at the costs of the raw materials and the OEM purchases that the brands did to generate their product.