You mean the drive the Xbox One S has and they can afford to sell that system as low as $180?
BREAKING THE BANK MY MAN!
http://technology.ihs.com/api/binary/582322 The UHD BR drive and the 2TD HDD COMBINED costed MS $88.50 in the One S. And this was in 2016. If you really think the 2 TB drive was only costing $38.50 I got some beach front property in arizona for you. I'll give you a hint on how much the HDD cost... The $500 GB model allowed them to drop the price by $100 while keeping all the same components. In other words the DR drive costed them jack shit.
Let alone how cheap it will be in 2020, to a company that owns a major stake in BR and doesn't need to pay licensing fees.
Even fucking humoring the idea that Sony could lower the price on the PS5 by $50 by simply removing the disc drive is bat shit insane. It costs nothing.