The bill of materials for 16GB of RAM isn’t remotely close to $200, it’s likely under $10. This is pure profit for Apple.
Chips get cheaper over time and there is a general expectation the base specs move forward without the price rising. The MacBook Pro has had 8 GB of RAM base since 2014, which is a century in chip time. 16 should have been the base several revisions ago and the long apple leaves it this way the worse it looks, since no one should be buying a “pro” device that needs upgrades to be competent.