TrendForce was predicting back in early 2019 that DDR4 RAM prices would see up to 35% cuts by Q2 2019, and this now appears to be indeed the case judging by the price trend data provided by CamelCamelCamel. These graphs also show that the DDR4 prices got halved compared to the peak prices of late 2017.
https://www.notebookcheck.net/DDR4-RAM-prices-continue-to-fall.415777.0.html