Why do better MC cartridges cost a fortune?

Active isolation like the Herzan (or similar from many others including KSI who make Vibraplanes) offers 99% isolation in all six dimensions. Passive such as Vibraplane maxes out at 95% or so and more effective in vertical than horizontal. Also latter requires a compressor for air supply. Cost is 30-40% of active however and certainly will give great results, as will other passive approaches such as Minus-K, do note however that the latter need to be loaded as specified for best results whereas active platforms perform under any load. So, many ways to slay the isolation dragon 🐉 

Yeah, this could be interesting dilemma for some. If you have $10k to upgrade your analog front end and your table arm and phono seem just fine but cartridge and isolation could be better, what do you do? Do you spend it all on Herzan active, supercartridge or do 3/7 split and get Minus-K platform and another cartridge? And how can you know in advance? I suppose, you can return the platforms if bought from authorized dealers or directly, though. But not cartridges. The answer to this question is, I think, you have to develop 'audiophile instinct'. It will not always be right but in most cases it will.

They charge and we gladly pay? And you have to retip or replace it soon enough. Most of them come from Japan. They sure know how to do business, don’t they?

No, the manufacturer is the poor one.
The real winners are those in the following distributor chain and when we go down to the core... your "enemy" is the audiophile next to you who wants to spend more :-)
Supported by deaf reviewers ....

Syntax, you are right too, but I didn't want to go into this openly, though indirectly I did. 'Audiophile class warfare' is something that we should try and avoid. Yes, if at least half of all audiophiles everywhere stop paying these insane amounts for the cartridges, things would probably get better for most. As for the distributors, that's another interesting story, and it goes far beyond audio and the US. Even French farmers suffer not to mention African miners.
Deaf reviewers... I don't have an impression that most of them are deaf, but if they say everything they really think their livelihood will almost certainly get very insecure. Do you meet many people who are ready for that?

@syntax -so nice to see you here. Been a while. I hope you are still having fun. I am! regards,
bill