Disk Drive Prices 1955-2019 (a professor graphs the trend the cheapest price/MB since 1955, last updated 2019Aug17, I'll link the actual data table in comments) : r/DataHoarder
Apple MacBook Pro 13.3" (256GB SSD, Intel Core i5 8th Gen., 2.40 GHz, 8GB) Laptop - Space Gray - MV962LL/A (May, 2019) for sale online | eBay
SSD prices will continue to tumble in 2019 says report - Components - News - HEXUS.net
Are SSDs Approaching Price Parity with HDDs? – The SSD Guy Blog
SSD prices keep falling in 2019: hard disk bears the brunt again