Deur Nandric, collecting cartridges is one of the most rational obsessions I can imagine 😊. Not at all like Tulips or Magical Financial Products.....
But it's not always easy to explain why certain 'objects' are expensive. Scarcity is one reason, obviously. In the 17th century pepper was scarce in the West and the Indian Company controlled the market, they were one of the first monopolists.
Desire and obsession is another, often fuelled by agressive brand marketing and peer pressure. This is how luxury markets like designer fashion operate: $1000 sneakers or $10k handbags anyone? There's absolutely no relation between the actual cost of making these products (modern slavery) and their market price.
But when both reasons coincide, prices really explode. Like in fine arts, classic cars and any number of truly rare objects of cultural importance.
Where does this leave our little hobby? Some 'old stuff' is rare and desirable because of their classic design, performance or reputation. Some Turntables and even Cartridges do apply. Some of the 'new stuff' is rare because it is manufactured in 'limited editions'. The high prices make these products desirable as 'trophies for the rich'. Their validity as high quality products is justified by glowing reviews of the audio 'journalists', who are an extension of the marketing strategy.
Everybody has to decide for themselves if they want to play along with their game.....