That is not to say there is no price-fixing going on, just that I really can't see a correlation with DDR generations.
And regardless, you could flip it around and ask, what will we do in x years when the next shortage comes along and we have no fabs? (And that shortage of course could well be an imposed one from an unfriendly nation.)
RAM being a staple of the computing industry you have to wonder if there aren't people cleaning up on this, it would be super easy to create an artificial shortage given the low number of players in this market. In contrast, say the price of gasoline, has been remarkably steady with one notable outlier with a very easy to verify and direct cause.