I know, first just let me say sorry for being the 1,000th person to make a Kat topic, but is it even worth farming?
Since the last event (one which I wasn't here for) was easily abused, "normal" Kat cowls are only worth about 8-10k CE(Unbind fee included). Now that abuse isn't possible, the reward is much MUCH harder to achieve with the value still being "meh".
You could say that the farming is for the book, not the pages, but the book is so rare that you probably won't come across it even if you farm, like people who play the lotto every day. It'll probably drop on someone who wasn't farming for it and just happened to come across a Black Kat.
If you decided to farm 200 pages for a "normal" cowl, that time spent farming could probably have gone to farming crowns instead, and then buying a cowl sooner than you could have farmed one. But I don't really know :p, since there's no official drop rates of pages/books, it's hard to make conclusions on what's worth doing. But what do you think?
I got 4 pages on the first day and gave up after discovering this event only lasts a week. The grinding is quite tedious.