They even have techniques to extract the eggs without killing the fish.
https://www.greatbritishchefs.com/features/ethical-caviar-fa...
https://californiacaviar.com/pages/our-story
https://www.finedininglovers.com/article/meet-frances-no-kil...
Not killing the fish is an obvious way to increase the farm's yield so I imagine most producers are interested in it. Sturgeon meat isn't particularly demanded either...
There are many kinds of fish which are used to make caviar. Some are more affordable than others:
https://www.gourmetfoodstore.com/caviar/
Myself, I really want to give Paddlefish a try. Strange beasts!
its really a great example of how people assign importance to things based on their price or scarcity, and that has nothing to do with anything related to the uniqueness or peculiarity of taste
Cf. Oranges during the war.