I'm a Hardware expert so you have to listen to me, Sony accidently ordered millions of Vita OLED screens after they had already changed the Vita screens to LCD but because the desert where Governments and Corporations love to hide their shit was full of dumped ET carts, they had no alternative but to keep them hidden in the warehouse that warehouse unbeknownst to them also housed another secret, a batch of prototype Virtual boy 2's.
It was during a search and destroy mission to eliminate any remnants of that dark past that Nintendo found those Vita screens and made a deal where Sony got to save years of R&D costs simply by readying those Virtual boy 2 Prototypes for mass production and branding them PSVR 2 and in return Nintendo received the OLED screens free of charge, but unfortunately Nintendo forgetting to account for the labour costs involved in glueing the Vita screens together and then cutting them to fit the Switch.
Breaking news.. My connections at Nintendo have assured me that using the very best accounting practices that can be procured from the interwebz the actual cost is $100 per unit so in their own words "Nintendo is once again generously subsidising it customers and should be praised for doing so".
Just got off the phone with my uncle who works at Nintendo (well more of an uncle-in-law; he's Japanese, and I'm not), he made me promise not to tell anyone that Nintendo plans to maintain the same profit margins when it inevitably does a price drop for the Switch in the future by stealthily removing the brightness sensor entirely. The nickel/dime they save per unit is roughly equal to the $50 that will be slashed from each model.