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 Grey - MV962X/A (May, 2019) for sale online | eBay
Western Digital's fastest SSD is at its lowest price on Amazon | Eurogamer.net