COC 19 was never in the same league as COC 23.
Apparently COC 19 had its art swiped for an album cover for some band...I'm not 100% sure on the details there regarding art usage (I need to read Craig Yoes Haunted Horror 1 hardcover. There might be more info there or perhaps another collector can chime in) but the popularity of COC19 is linked to this reason.
When viewing the covers of BC 50, TOT 15, and COC23 next to each other, it becomes clear who makes up the Top Harvey Horror Trio! ?
That said COC 19 is still a decent cover but it's a big step down. I also think COC 16 is a pretty amazing cover that does not get as much attention as it should.