Slow SSDs have gone down in price, but fast SSDs are still expensive. For example, you can get a 500GB Samsung 850 for about $130 but a Samsung 960 evo costs $

Slow SSDs have gone down in price, but fast SSDs are still expensive. For example, you can get a 500GB Samsung 850 for about $130 but a Samsung 960 evo costs $250, and then another $100 on top of that for the 960 pro. Those 3 drives range from 600MB/sec to 2222MB/sec linear reads, the fastest costing the same as a 600MB/sec SSD did 3 years ago. The demand for slow RAM drops precipitously after the whatever Intel chipsets use it stop being used in new systems (not sure if the same is true in the embedded market). For example, nobody's buying DDR2 these days. So the economies of scale dissipate and fabs retool faster. So while both devices have economies of scale, SSDs have an extra dimension to their demand curve for performance that allows for slower higher density chips to still be profitable.