Actually, it’s a price correction, not an increase, Apple tells The Verge ...
Apple doubles the price for entry-level MacBook Pro RAM upgrade
https://www.theverge.com/2020/6/1/21277236/macbook-pro-entry-level-price-apple-ram-upgrade
"The price increase is actually a price correction, Apple tells The Verge. The price to upgrade RAM from 8GB to 16GB is $200 on other Macs, including the iMac and MacBook Air, and this change is meant to keep the fee consistent."
https://www.theverge.com/2020/6/1/21277236/macbook-pro-entry-level-price-apple-ram-upgrade
"The price increase is actually a price correction, Apple tells The Verge. The price to upgrade RAM from 8GB to 16GB is $200 on other Macs, including the iMac and MacBook Air, and this change is meant to keep the fee consistent."