Of course Intel segmenting ECC out of the client market is a major factor…
… which does not mean other factors are "irrelevant"…
… and also the price differential in ECC memory is not only a factor but also a metric as it shows that ECC memory has a "non-mainstay" surcharge created by the vast majority of users going for non-ECC. If demand were equal, the price would be 9/8 = 1.125×.
Demand cant be equal when nothing on the desktop supported ECC for the last 22 years (2017-1995), and even now its only a select fragment of ~28% market share. Things would look different if you could reuse server ram in any desktop board. 16-24GB DDR3 ECC ram sticks sell at 4x discount compared to regular old DDR3. I havent looked into DDR4 difference.
… which does not mean other factors are "irrelevant"…
… and also the price differential in ECC memory is not only a factor but also a metric as it shows that ECC memory has a "non-mainstay" surcharge created by the vast majority of users going for non-ECC. If demand were equal, the price would be 9/8 = 1.125×.