Oh, yeah sure.
Well being cheaper mainly depends on the relative cost I think. Having i.e. Well of Misery up and gathering lots of D gems could make 25 D gems less expensive then 10 W if you have those scarce and need the blue ones for i.e. frost brands (or boots of quickness for the guys wielding frost brands, which would need those more than the Drainer in the backline
). Which is not unlikely as if you have lots of D gems you prolly have many undeads with CR100% so tossing freeze death around is a very nice idea
