... And then you get biased as soon as it comes to your army. When comparing two alien items (book of meladys and ancient plaque) you found two small advantage one has over another (completely not worth the point difference imho) and concluded that the cost gap is ok.Cross-army comparisons are generally a good starting point(IMO) - but when someone claims something army A pretty much never takes is undercosted compared to the thing army B takes in most of their lists, you need to take a look at the bigger picture.
When it came to your own army (arcane knoweledge against asfad) with your "item" being clearly better and cheaper than the other, you took another approach and explained at length why it is justified. I could try and find the faults in your reasoning or come up with my own, leading to completely opposite conclusions. But in the end, we will both stay where we started, right?
Kinda assuming SA isn't one of my armies there bud. They are, actually.
And as a SA player, I could really get outraged at how much better Book is (seriously, 1-dicing is normally not viable... but with the Book? Yeah, you can do it)... but I also know how bonkers the Cuatl is, so it's fair that HBE get a stronger version of Plaque, HBE need some magic strength too.
I'm not defending Arcane Knowledge because it's something I'd ever consider taking for more than a millisecond. I'm defending it because this like you seeing someone ranting about how overpowered and underpriced Sea Guard are.
Seriously, it is just not an upgrade I'd consider taking, ever. The only worse Blood Power is the OTHER Nosferatu "general" Blood Power (Forbidden Path is both inaccurately named and also actively makes the model you take it on worse. I wouldn't take Forbidden Path if it cost NEGATIVE 25 points).
Like, I'd happily accept jacking it's price up to 150 just to make this argument go away, because that would be taking it from "unplayable" to "unplayable".
(It doesn't help that on a Nosferatu, Arcane Knowledge is strictly worse than Asfad, as they already know the hereditary. Seriously, Arcane Knowledge gets worse and worse the more I think about it.)